If you have been reading about robustness and want a single page that covers the useful parts, this is it: definitions, context, how it is studied, and the questions that come up repeatedly.
Last reviewed on 2026-03-28. Where a claim depends on a specific study, the study is described rather than over-claimed.
Developing an HPLC method begins with defining the purpose, such as quantifying a main component, measuring impurities, or confirming identity. Analysts select separation mode, column, mobile phase, detection, and sample preparation based on analyte properties and matrix. Experiments vary solvent strength, pH, buffer type, and temperature to achieve resolution between critical peaks. The goal is a robust method that produces reliable results across instruments and operators. Method development often involves trial runs and statistical optimization.
Validation demonstrates that a method is suitable for its intended use. Typical performance characteristics include accuracy, precision, specificity, linearity, range, limit of detection, limit of quantitation, and robustness. Regulators and standards organizations provide frameworks, but specific requirements depend on the application and jurisdiction. System suitability tests are run before sample analysis to confirm resolution, peak symmetry, retention time repeatability, and sensitivity. A validated method is not permanently fixed; changes may require partial or full revalidation.
Method validation examines whether an HPLC procedure is suitable for its intended purpose. Common parameters include accuracy, precision, specificity, linearity, range, detection limit, quantification limit, and robustness. Accuracy describes closeness to a true or accepted value, while precision describes agreement among repeated measurements. Specificity shows whether the method can measure the analyte without interference from related substances. Robustness tests small deliberate changes in flow, temperature, or solvent composition. Validation is not a one-time event; methods may need partial revalidation after changes to instruments, columns, sample handling, or specification limits. Regulatory guidance provides frameworks, but some details remain method-specific.
Regulatory and pharmacopeial texts shape how HPLC testing is performed and documented. The International Council for Harmonisation provides validation guidance, while pharmacopeias publish general chromatography chapters and monographs for specific materials. Accreditation standards such as ISO/IEC 17025 address laboratory competence and traceability. Inspectors may review instrument qualification, analyst training, reference material control, and electronic records. Open questions include how best to validate methods for new complex products and how to handle automated data processing. Laboratories generally resolve these issues through risk assessment, method lifecycle management, and documented scientific justification.
In quality control laboratories, HPLC testing supports batch release, raw material checks, stability studies, and impurity profiling. A validated method defines sample preparation, instrument settings, calibration, and acceptance criteria. Analysts compare results with specifications and investigate out-of-specification outcomes before a batch is approved. Documentation includes chromatograms, integration records, audit trails, and reagent details. Because results influence product decisions, laboratories follow formal quality systems and data integrity rules. The exact tests and limits depend on the material, its intended use, and the applicable regulatory framework.
| Property | Value | Notes |
|---|---|---|
| Validation parameter | Accuracy | Closeness of measured value to accepted reference value |
| Validation parameter | Precision | Agreement among repeated measurements under specified conditions |
| System suitability check | Resolution ≥ 1.5 | Baseline separation between critical peak pair |
| System suitability check | Tailing factor ≤ 2.0 | Common target for peak symmetry |
| Documentation | Validation report | Summarizes experiments, acceptance criteria, and conclusions |
Data handling and documentation are central to HPLC quality control. Electronic systems should have audit trails that record changes to methods, sequences, and results. Integration parameters, such as peak baseline and threshold, can affect reported areas and must be defined in advance. Out-of-specification results trigger a structured investigation that may include reanalysis, instrument checks, and review of sample preparation. Regulatory inspections often examine raw data, audit trails, and training records to verify that reported results are traceable and reliable.
Method validation establishes that an HPLC procedure is suitable for its intended use. Key parameters include accuracy, precision, specificity, linearity, range, limit of detection, limit of quantitation, and robustness. Accuracy measures agreement with a true or accepted value, while precision describes repeatability and intermediate precision. Specificity confirms that the method measures the analyte without interference from impurities, degradants, or excipients. Validation is documented in a protocol and report, and acceptance criteria are set before experiments begin. Regulatory guidance varies by region, but the general principles are widely harmonized.
System suitability testing is performed before and during analytical runs to confirm that the instrument and method are working as expected. Common checks include retention time, peak area, resolution between critical pairs, tailing factor, and theoretical plate count. Results are compared with predefined limits, and a failed check requires investigation before sample results are reported. Quality control samples at low, middle, and high concentrations are injected at intervals to monitor accuracy and precision. Blank injections detect carryover and contamination, while control charts track performance over time.
Method validation demonstrates that an analytical procedure is suitable for its intended purpose. Typical validation characteristics include accuracy, precision, specificity, linearity, range, limit of detection, limit of quantitation, and robustness. Regulatory guidance from bodies such as the International Council for Harmonisation and the United States Pharmacopeia outlines expectations, though specific criteria depend on the product and method. System suitability tests are run before sample analysis to confirm resolution, peak symmetry, column efficiency, and injection repeatability. Failure of these checks can invalidate a batch of measurements.
Practical HPLC testing depends on careful sample preparation and instrument maintenance. Samples may require filtration, dilution, pH adjustment, or extraction to avoid column damage and matrix interference. Mobile phases are degassed and filtered, and columns are equilibrated before injection. Common problems include peak tailing, baseline drift, ghost peaks, carryover, and co-elution of analytes. Documentation of instrument logs, calibration records, and electronic audit trails supports data integrity and traceability. Ongoing training and routine maintenance help reduce variability between analysts and laboratories.
Key performance measures include retention time, peak area, peak height, resolution, tailing factor, and plate count. Retention time helps identify a peak under fixed conditions, but confirmation often requires a second method or detector. Peak area and height relate to concentration through calibration curves, which may be linear or nonlinear depending on the detector response. Resolution describes separation between adjacent peaks, while tailing factor and plate count describe peak shape and column efficiency. Performance checks verify these values before and during a run to confirm that the instrument is performing within limits.
High-performance liquid chromatography testing separates components of a liquid sample by forcing a mobile phase through a packed column. The stationary phase inside the column interacts with analytes to different degrees, so each compound exits at a characteristic retention time. A pump delivers solvent at controlled flow and pressure, while an injector introduces a precise sample volume. Detectors such as ultraviolet-visible, fluorescence, refractive index, or mass spectrometric instruments record the separated bands. The resulting chromatogram provides qualitative and quantitative information about the mixture.
Detection commonly uses ultraviolet-visible absorbance, fluorescence, refractive index, or mass spectrometry. Ultraviolet detection depends on molecular chromophores that absorb light at specific wavelengths. Mass spectrometry provides mass information and sensitive quantification, often after electrospray ionization. Before sample batches, performance checks examine resolution, elution time repeatability, peak symmetry, and plate count. Matrix effects and co-elution remain recognized uncertainties; formal validation studies and orthogonal detection help address them. Detector choice depends on analyte properties and required sensitivity.
High-performance liquid chromatography, or HPLC, separates dissolved compounds by passing a liquid mobile phase through a packed column. Components distribute differently between the stationary phase and the moving liquid, so they travel at different speeds and exit at different times. A detector records these eluting bands as peaks, and peak area or height relates to amount. The technique supports testing in pharmaceuticals, foods, environmental samples, and industrial chemicals. Quantification usually depends on calibration with known standards.
=== Role in apoptosis === Cytochrome c was also discovered in 1996 by Xiaodong Wang to have an intermediate role in apoptosis, a controlled form of cell death used to kill cells in the process of development or in response to infection or DNA damage. Cytochrome c binds to cardiolipin in the inner mitochondrial membrane, thus anchoring its presence and keeping it from releasing out of the mitochondria and initiating apoptosis. While the initial attraction between cardiolipin and cytochrome c is electrostatic due to the extreme positive charge on cytochrome c, the final interaction is hydrophobic, where a hydrophobic tail from cardiolipin inserts itself into the hydrophobic portion of cytochrome c. During the early phase of apoptosis, mitochondrial ROS production is stimulated, and cardiolipin is oxidized by a peroxidase function of the cardiolipin–cytochrome c complex. The hemoprotein is then detached from the mitochondrial inner membrane and can be extruded into the soluble cytoplasm through pores in the outer membrane. The sustained elevation in calcium levels precedes cyt c release from the mitochondria. The release of small amounts of cyt c leads to an interaction with the IP3 receptor (IP3R) on the endoplasmic reticulum (ER), causing ER calcium release. The overall increase in calcium triggers a massive release of cyt c, which then acts in the positive feedback loop to maintain ER calcium release through the IP3Rs. This explains how the ER calcium release can reach cytotoxic levels. This release of cytochrome c in turn activates caspase 9, a cysteine protease.
It makes determinations about what objects to prioritize based on what is especially important to Congress or potentially interesting for the public. The 15 million digitized items represent less than 10% of the library's total 160-million-item collection. The library has chosen not to participate in other digital library projects such as Google Books and the Digital Public Library of America, although it has supported the Internet Archive project.
Replacing natural polyunsaturated fatty acids (PUFA) with deuterated PUFA (dPUFA), which have deuterium in place of the bis-allylic hydrogens, can prevent cell death induced by erastin or RSL3. These deuterated PUFAs effectively inhibit ferroptosis and various chronic degenerative diseases associated with ferroptosis. Live-cell imaging has been used to observe the morphological changes that cells undergo during ferroptosis. Initially the cell contracts and then begins to swell. Perinuclear lipid assembly is observed immediately before ferroptosis occurs. After the process is complete, lipid droplets are redistributed throughout the cell (see GIF on right side).
== Medical uses == The primary application for phentolamine is for the control of hypertensive emergencies, most notably due to pheochromocytoma. It also has usefulness in the treatment of cocaine-induced cardiovascular complications, where one would generally avoid β-blockers (e.g., metoprolol), as they can cause unopposed α-adrenergic mediated coronary vasoconstriction, worsening myocardial ischemia and hypertension. Phentolamine is not a first-line agent for this indication. Phentolamine should only be given to patients who do not fully respond to benzodiazepines, nitroglycerin, and calcium channel blockers. When given by injection, it causes blood vessels to dilate, thereby increasing blood flow. When injected into the penis (intracavernosal), it increases blood flow to the penis, which results in an erection. It may be stored in crash carts to counteract severe peripheral vasoconstriction secondary to extravasation of peripherally placed vasopressor infusions, typically of norepinephrine. Epinephrine infusions are less vasoconstrictive than norepinephrine as they primarily stimulate β receptor more than α receptors, but the effect remains dose-dependent. Phentolamine also has diagnostic and therapeutic roles in complex regional pain syndrome (CRPS). Phentolamine is marketed in the dental field as a local anesthetic reversal agent. Branded as OraVerse, it is a phentolamine mesylate injection designed to reverse the local vasoconstrictor properties used in many local anesthetics to prolong anesthesia.
Sources: en.wikipedia.org
=== Personal life and death === Dyson married his first wife, the Swiss mathematician Verena Huber, on 11 August 1950. They had two children, Esther and George, before divorcing in 1958. In November 1958 he married Imme Jung, with whom he had four daughters. Dyson died on 28 February 2020 at Penn Medicine Princeton Medical Center in Plainsboro Township, New Jersey, from complications following a fall. He was 96.
===== MeSH D08.811.913.696 – phosphotransferases (EC 2.7) ===== MeSH D08.811.913.696.175 – diphosphotransferases MeSH D08.811.913.696.175.300 – gtp pyrophosphokinase MeSH D08.811.913.696.175.650 – ribose-phosphate pyrophosphokinase MeSH D08.811.913.696.175.825 – thiamin pyrophosphokinase MeSH D08.811.913.696.310 – myosin type iii MeSH D08.811.913.696.445 – nucleotidyltransferases MeSH D08.811.913.696.445.035 – n-acylneuraminate cytidylyltransferase MeSH D08.811.913.696.445.184 – choline-phosphate cytidylyltransferase MeSH D08.811.913.696.445.308 – dna nucleotidyltransferases MeSH D08.811.913.696.445.308.300 – dna-directed dna polymerase MeSH D08.811.913.696.445.308.300.112 – dna polymerase beta MeSH D08.811.913.696.445.308.300.225 – dna polymerase i MeSH D08.811.913.696.445.308.300.230 – dna polymerase ii MeSH D08.811.913.696.445.308.300.235 – dna polymerase iii MeSH D08.811.913.696.445.308.300.750 – RNA-directed dna polymerase MeSH D08.811.913.696.445.308.300.750.375 – hiv-1 reverse transcriptase MeSH D08.811.913.696.445.308.300.750.750 – telomerase MeSH D08.811.913.696.445.308.300.875 – taq polymerase MeSH D08.811.913.696.445.308.325 – dna nucleotidylexotransferase MeSH D08.811.913.696.445.400 – glucose-1-phosphate adenylyltransferase MeSH D08.811.913.696.445.600 – nicotinamide-nucleotide adenylyltransferase MeSH D08.811.913.696.445.625 – 2',5'-oligoadenylate synthetase MeSH D08.811.913.696.445.650 – polynucleotide adenylyltransferase MeSH D08.811.913.696.445.692 – rec a recombinases MeSH D08.811.913.696.445.735 – rna nucleotidyltransferases MeSH D08.811.913.696.445.735.265 – dna, catalytic MeSH D08.811.913.696.445.735.270 – dna-directed rna polymerases MeSH D08.811.913.696.445.735.270.375 – dna primase MeSH D08.811.913.696.445.735.270.750 – rna polymerase i MeSH D08.811.913.696.445.735.270.762 – rna polymerase ii MeSH D08.811.913.696.445.735.270.775 – rna polymerase iii MeSH D08.811.913.696.445.735.270.887 – rna polymerase sigma 54 MeSH D08.811.913.696.445.735.532 – polyribonucleotide nucleotidyltransferase MeSH D08.811.913.696.445.735.630 – q beta replicase MeSH D08.811.913.696.445.735.720 – rna helicases MeSH D08.811.913.696.445.735.720.500 – eukaryotic initiation factor-4a MeSH D08.811.913.696.445.735.780 – rna replicase MeSH D08.811.913.696.445.735.917 – rna, ribosomal, self-splicing MeSH D08.811.913.696.445.800 – sulfate adenylyltransferase MeSH D08.811.913.696.445.825 – transposases MeSH D08.811.913.696.445.825.500 – hiv integrase MeSH D08.811.913.696.445.837 – transposon resolvases MeSH D08.811.913.696.445.850 – UDP-glucose—hexose-1-phosphate uridylyltransferase MeSH D08.811.913.696.445.875 – UTP—glucose-1-phosphate uridylyltransferase MeSH D08.811.913.696.445.900 – UTP—hexose-1-phosphate uridylyltransferase MeSH D08.811.913.696.445.950 – vdj recombinases MeSH D08.811.913.696.620 – phosphotransferases (alcohol group acceptor) MeSH D08.811.913.696.620.010 – adenosine kinase MeSH D08.811.913.696.620.155 – choline kinase MeSH D08.811.913.696.620.175 – deoxycytidine kinase MeSH D08.811.913.696.620.200 – diacylglycerol kinase MeSH D08.811.913.696.620.225 – fructokinases MeSH D08.811.913.696.620.225.850 – phosphofructokinases MeSH D08.811.913.696.620.225.850.500 – phosphofructokinase-1 MeSH D08.811.913.696.620.225.850.500.249 – phosphofructokinase-1, liver type MeSH D08.811.913.696.620.225.850.500.500 – phosphofructokinase-1, muscle type MeSH D08.811.913.696.620.225.850.500.750 – phosphofructokinase-1, type c MeSH D08.811.913.696.620.225.850.750 – phosphofructokinase-2 MeSH D08.811.913.696.620.240 – galactokinase MeSH D08.811.913.696.620.250 – glucokinase MeSH D08.811.913.696.620.275 – glycerol kinase MeSH D08.811.913.696.620.300 – hexokinase MeSH D08.811.913.696.620.475 – kanamycin kinase MeSH D08.811.913.696.620.525 – 1-phosphatidylinositol 3-kinase MeSH D08.811.913.696.620.550 – 1-phosphatidylinositol 4-kinase MeSH D08.811.913.696.620.650 – phosphoenolpyruvate sugar phosphotransferase system MeSH D08.811.913.696.620.680 – polynucleotide 5'-hydroxyl-kinase MeSH D08.811.913.696.620.682 – protein kinases MeSH D08.811.913.696.620.682.650 – phosphorylase kinase MeSH D08.811.913.696.620.682.700 – protein-serine-threonine kinases MeSH D08.811.913.696.620.682.700.062 – activin receptors MeSH D08.811.913.696.620.682.700.062.500 – activin receptors, type i MeSH D08.811.913.696.620.682.700.062.750 – activin receptors, type ii MeSH D08.811.913.696.620.682.700.109 – bone morphogenetic protein receptors MeSH D08.811.913.696.620.682.700.109.500 – bone morphogenetic protein receptors, type i MeSH D08.811.913.696.620.682.700.109.750 – bone morphogenetic protein receptors, type ii MeSH D08.811.913.696.620.682.700.125 – ca(2+)-calmodulin dependent protein kinase MeSH D08.811.913.696.620.682.700.125.500 – myosin-light-chain kinase MeSH D08.811.913.696.620.682.700.140 – casein kinases MeSH D08.811.913.696.620.682.700.140.300 – casein kinase i MeSH D08.811.913.696.620.682.700.140.300.100 – casein kinase ialpha MeSH D08.811.913.696.620.682.700.140.300.200 – casein kinase idelta MeSH D08.811.913.696.620.682.700.140.300.300 – casein kinase iepsilon MeSH D08.811.913.696.620.682.700.140.600 – casein kinase ii MeSH D08.811.913.696.620.682.700.150 – cyclic nucleotide-regulated protein kinases MeSH D08.811.913.696.620.682.700.150.125 – cyclic amp-dependent protein kinases MeSH D08.811.913.696.620.682.700.150.125.500 – beta-adrenergic-receptor kinase MeSH D08.811.913.696.620.682.700.150.150 – cyclic gmp-dependent protein kinases MeSH D08.811.913.696.620.682.700.150.575 – protamine kinase MeSH D08.811.913.696.620.682.700.200 – cyclin-dependent kinases MeSH D08.811.913.696.620.682.700.200.067 – cdc2-cdc28 kinases MeSH D08.811.913.696.620.682.700.200.067.249 – cdc2 protein kinase MeSH D08.811.913.696.620.682.700.200.067.500 – cdc28 protein kinase, s cerevisiae MeSH D08.811.913.696.620.682.700.200.067.875 – cyclin-dependent kinase 5 MeSH D08.811.913.696.620.682.700.200.067.900 – cyclin-dependent kinase 9 MeSH D08.811.913.696.620.682.700.200.323 – cyclin-dependent kinase 2 MeSH D08.811.913.696.620.682.700.200.451 – cyclin-dependent kinase 4 MeSH D08.811.913.696.620.682.700.200.515 – cyclin-dependent kinase 6 MeSH D08.811.913.696.620.682.700.200.580 – maturation-promoting factor MeSH D08.811.913.696.620.682.700.200.580.500 – cdc2 protein kinase MeSH D08.811.913.696.620.682.700.250 – dna-activated protein kinase MeSH D08.811.913.696.620.682.700.300 – eif-2 kinase MeSH D08.811.913.696.620.682.700.429 – glycogen synthase kinases MeSH D08.811.913.696.620.682.700.429.500 – glycogen synthase kinase 3 MeSH D08.811.913.696.620.682.700.494 – i-kappa B kinase MeSH D08.811.913.696.620.682.700.559 – map kinase kinase kinases MeSH D08.811.913.696.620.682.700.559.100 – map kinase kinase kinase 1 MeSH D08.811.913.696.620.682.700.559.200 – map kinase kinase kinase 2 MeSH D08.811.913.696.620.682.700.559.300 – map kinase kinase kinase 3 MeSH D08.811.913.696.620.682.700.559.400 – map kinase kinase kinase 4 MeSH D08.811.913.696.620.682.700.559.500 – map kinase kinase kinase 5 MeSH D08.811.913.696.620.682.700.559.800 – proto-oncogene proteins c-mos MeSH D08.811.913.696.620.682.700.559.842 – raf kinases MeSH D08.811.913.696.620.682.700.559.842.249 – oncogene proteins v-raf MeSH D08.811.913.696.620.682.700.559.842.374 – proto-oncogene proteins b-raf MeSH D08.811.913.696.620.682.700.559.842.500 – proto-oncogene proteins c-raf MeSH D08.811.913.696.620.682.700.565 – mitogen-activated protein kinase kinases MeSH D08.811.913.696.620.682.700.565.100 – map kinase kinase 1 MeSH D08.811.913.696.620.682.700.565.200 – map kinase kinase 2 MeSH D08.811.913.696.620.682.700.565.300 – map kinase kinase 3 MeSH D08.811.913.696.620.682.700.565.400 – map kinase kinase 4 MeSH D08.811.913.696.620.682.700.565.500 – map kinase kinase 5 MeSH D08.811.913.696.620.682.700.565.600 – map kinase kinase 6 MeSH D08.811.913.696.620.682.700.565.700 – map kinase kinase 7 MeSH D08.811.913.696.620.682.700.567 – mitogen-activated protein kinases MeSH D08.811.913.696.620.682.700.567.342 – extracellular signal-regulated map kinases MeSH D08.811.913.696.620.682.700.567.342.500 – mitogen-activated protein kinase 1 MeSH D08.811.913.696.620.682.700.567.342.750 – mitogen-activated protein kinase 3 MeSH D08.811.913.696.620.682.700.567.342.875 – mitogen-activated protein kinase 6 MeSH D08.811.913.696.620.682.700.567.342.937 – mitogen-activated protein kinase 7 MeSH D08.811.913.696.620.682.700.567.513 – jnk mitogen-activated protein kinases MeSH D08.811.913.696.620.682.700.567.513.500 – mitogen-activated protein kinase 8 MeSH D08.811.913.696.620.682.700.567.513.750 – mitogen-activated protein kinase 9 MeSH D08.811.913.696.620.682.700.567.513.800 – mitogen-activated protein kinase 10 MeSH D08.811.913.696.620.682.700.567.878 – p38 mitogen-activated protein kinases MeSH D08.811.913.696.620.682.700.586 – oncogene protein v-akt MeSH D08.811.913.696.620.682.700.606 – phytochrome a MeSH D08.811.913.696.620.682.700.646 – proline-directed protein kinases MeSH D08.811.913.696.620.682.700.646.500 – cyclin-dependent kinases MeSH D08.811.913.696.620.682.700.646.500.500 – cdc2-cdc28 kinases MeSH D08.811.913.696.620.682.700.646.500.500.500 – cyclin-dependent kinase 5 MeSH D08.811.913.696.620.682.700.646.500.750 – cyclin-dependent kinase 2 MeSH D08.811.913.696.620.682.700.646.500.875 – cyclin-dependent kinase 4 MeSH D08.811.913.696.620.682.700.646.500.937 – cyclin-dependent kinase 6 MeSH D08.811.913.696.620.682.700.646.625 – glycogen synthase kinase 3 MeSH D08.811.913.696.620.682.700.646.750 – mitogen-activated protein kinases MeSH D08.811.913.696.620.682.700.646.750.249 – extracellular signal-regulated map kinases MeSH D08.811.913.696.620.682.700.646.750.249.500 – mitogen-activated protein kinase 1 MeSH D08.811.913.696.620.682.700.646.750.249.750 – mitogen-activated protein kinase 3 MeSH D08.811.913.696.620.682.700.646.750.249.875 – mitogen-activated protein kinase 6 MeSH D08.811.913.696.620.682.700.646.750.249.937 – mitogen-activated protein kinase 7 MeSH D08.811.913.696.620.682.700.646.750.374 – jnk mitogen-activated protein kinases MeSH D08.811.913.696.620.682.700.646.750.374.500 – mitogen-activated protein kinase 8 MeSH D08.811.913.696.620.682.700.646.750.374.750 – mitogen-activated protein kinase 9 MeSH D08.811.913.696.620.682.700.646.750.374.800 – mitogen-activated protein kinase 10 MeSH D08.811.913.696.620.682.700.646.750.843 – p38 mitogen-activated protein kinases MeSH D08.811.913.696.620.682.700.725 – protein kinase C MeSH D08.811.913.696.620.682.700.725.100 – protein kinase C-alpha MeSH D08.811.913.696.620.682.700.725.400 – protein kinase C-delta MeSH D08.811.913.696.620.682.700.725.750 – protein kinase C-epsilon MeSH D08.811.913.696.620.682.700.755 – proto-oncogene proteins C-akt MeSH D08.811.913.696.620.682.700.759 – proto-oncogene proteins C-bcr MeSH D08.811.913.696.620.682.700.776 – proto-oncogene proteins C-pim-1 MeSH D08.811.913.696.620.682.700.827 – rhodopsin kinase MeSH D08.811.913.696.620.682.700.862 – ribosomal protein s6 kinases MeSH D08.811.913.696.620.682.700.862.249 – ribosomal protein s6 kinases, 70-kda MeSH D08.811.913.696.620.682.700.862.500 – ribosomal protein s6 kinases, 90-kda MeSH D08.811.913.696.620.682.725 – protein-tyrosine kinase MeSH D08.811.913.696.620.682.725.049 – focal adhesion protein-tyrosine kinases MeSH D08.811.913.696.620.682.725.049.500 – focal adhesion kinase 1 MeSH D08.811.913.696.620.682.725.049.750 – focal adhesion kinase 2 MeSH D08.811.913.696.620.682.725.200 – mitogen-activated protein kinase kinases MeSH D08.811.913.696.620.682.725.200.100 – map kinase kinase 1 MeSH D08.811.913.696.620.682.725.200.200 – map kinase kinase 2 MeSH D08.811.913.696.620.682.725.200.300 – map kinase kinase 3 MeSH D08.811.913.696.620.682.725.200.400 – map kinase kinase 4 MeSH D08.811.913.696.620.682.725.200.500 – map kinase kinase 5 MeSH D08.811.913.696.620.682.725.200.600 – map kinase kinase 6 MeSH D08.811.913.696.620.682.725.200.700 – map kinase kinase 7 MeSH D08.811.913.696.620.682.725.300 – proto-oncogene proteins c-fes MeSH D08.811.913.696.620.682.725.400 – receptor protein-tyrosine kinases MeSH D08.811.913.696.620.682.725.400.020 – fms-like tyrosine kinase 3 MeSH D08.811.913.696.620.682.725.400.024 – receptor, fibroblast growth factor, type 1 MeSH D08.811.913.696.620.682.725.400.037 – receptor, fibroblast growth factor, type 2 MeSH D08.811.913.696.620.682.725.400.043 – receptor, fibroblast growth factor, type 3 MeSH D08.811.913.696.620.682.725.400.046 – receptor, fibroblast growth factor, type 4 MeSH D08.811.913.696.620.682.725.400.050 – proto-oncogene proteins c-kit MeSH D08.811.913.696.620.682.725.400.075 – proto-oncogene proteins c-met MeSH D08.811.913.696.620.682.725.400.087 – proto-oncogene proteins c-ret MeSH D08.811.913.696.620.682.725.400.100 – receptor, epidermal growth factor MeSH D08.811.913.696.620.682.725.400.150 – receptor, erbb-2 MeSH D08.811.913.696.620.682.725.400.175 – receptor, erbb-3 MeSH D08.811.913.696.620.682.725.400.185 – receptor, igf type 1 MeSH D08.811.913.696.620.682.725.400.200 – receptor, insulin MeSH D08.811.913.696.620.682.725.400.500 – receptor, macrophage colony-stimulating factor MeSH D08.811.913.696.620.682.725.400.660 – receptor, trka MeSH D08.811.913.696.620.682.725.400.700 – receptor, trkb MeSH D08.811.913.696.620.682.725.400.800 – receptor, trkc MeSH D08.811.913.696.620.682.725.400.850 – receptors, eph family MeSH D08.811.913.696.620.682.725.400.850.050 – receptor, epha1 MeSH D08.811.913.696.620.682.725.400.850.100 – receptor, epha2 MeSH D08.811.913.696.620.682.725.400.850.150 – receptor, epha3 MeSH D08.811.913.696.620.682.725.400.850.200 – receptor, epha4 MeSH D08.811.913.696.620.682.725.400.850.250 – receptor, epha5 MeSH D08.811.913.696.620.682.725.400.850.300 – receptor, epha6 MeSH D08.811.913.696.620.682.725.400.850.400 – receptor, epha7 MeSH D08.811.913.696.620.682.725.400.850.500 – receptor, epha8 MeSH D08.811.913.696.620.682.725.400.850.600 – receptor, ephb1 MeSH D08.811.913.696.620.682.725.400.850.650 – receptor, ephb2 MeSH D08.811.913.696.620.682.725.400.850.700 – receptor, ephb3 MeSH D08.811.913.696.620.682.725.400.850.750 – receptor, ephb4 MeSH D08.811.913.696.620.682.725.400.850.800 – receptor, ephb5 MeSH D08.811.913.696.620.682.725.400.900 – receptors, platelet-derived growth factor MeSH D08.811.913.696.620.682.725.400.900.500 – receptor, platelet-derived growth factor alpha MeSH D08.811.913.696.620.682.725.400.900.750 – receptor, platelet-derived growth factor beta MeSH D08.811.913.696.620.682.725.400.925 – receptors, tie MeSH D08.811.913.696.620.682.725.400.925.249 – receptor, tie-1 MeSH D08.811.913.696.620.682.725.400.925.500 – receptor, tie-2 MeSH D08.811.913.696.620.682.725.400.950 – receptors, vascular endothelial growth factor MeSH D08.811.913.696.620.682.725.400.950.100 – vascular endothelial growth factor receptor-1 MeSH D08.811.913.696.620.682.725.400.950.200 – vascular endothelial growth factor receptor 2 MeSH D08.811.913.696.620.682.725.400.950.300 – vascular endothelial growth factor receptor-3 MeSH D08.811.913.696.620.682.725.500 – proto-oncogene proteins c-abl MeSH D08.811.913.696.620.682.725.800 – src-family kinases MeSH D08.811.913.696.620.682.725.800.315 – lymphocyte specific protein tyrosine kinase p56(lck) MeSH D08.811.913.696.620.682.725.800.472 – oncogene protein pp60(v-src) MeSH D08.811.913.696.620.682.725.800.551 – proto-oncogene proteins c-fyn MeSH D08.811.913.696.620.682.725.800.590 – proto-oncogene proteins c-hck MeSH D08.811.913.696.620.682.725.800.610 – proto-oncogene proteins c-yes MeSH D08.811.913.696.620.682.725.800.630 – proto-oncogene proteins pp60(c-src) MeSH D08.811.913.696.620.682.725.900 – zap-70 protein-tyrosine kinase MeSH D08.811.913.696.620.685 – pyridoxal kinase MeSH D08.811.913.696.620.695 – pyruvate kinase MeSH D08.811.913.696.620.750 – thymidine kinase MeSH D08.811.913.696.620.800 – uridine kinase MeSH D08.811.913.696.630 – phosphotransferases (carboxyl group acceptor) MeSH D08.811.913.696.630.025 – acetate kinase MeSH D08.811.913.696.630.050 – aspartate kinase MeSH D08.811.913.696.630.050.050 – aspartokinase homoserine dehydrogenase MeSH D08.811.913.696.630.700 – phosphoglycerate kinase MeSH D08.811.913.696.640 – phosphotransferases (nitrogenous group acceptor) MeSH D08.811.913.696.640.025 – arginine kinase MeSH D08.811.913.696.640.150 – creatine kinase MeSH D08.811.913.696.640.150.500 – creatine kinase, bb form MeSH D08.811.913.696.640.150.625 – creatine kinase, mb form MeSH D08.811.913.696.640.150.750 – creatine kinase, mitochondrial form MeSH D08.811.913.696.640.150.875 – creatine kinase, mm form MeSH D08.811.913.696.645 – phosphotransferases (paired acceptors) MeSH D08.811.913.696.645.700 – pyruvate, orthophosphate dikinase MeSH D08.811.913.696.650 – phosphotransferases (phosphate group acceptor) MeSH D08.811.913.696.650.025 – adenylate kinase MeSH D08.811.913.696.650.150 – atp synthetase complexes MeSH D08.811.913.696.650.150.500 – proton-translocating atpases MeSH D08.811.913.696.650.150.500.249 – bacterial proton-translocating atpases MeSH D08.811.913.696.650.150.500.500 – chloroplast proton-translocating atpases MeSH D08.811.913.696.650.150.500.750 – mitochondrial proton-translocating atpases MeSH D08.811.913.696.650.150.500.875 – vacuolar proton-translocating atpases MeSH D08.811.913.696.650.450 – guanylate kinase MeSH D08.811.913.696.650.550 – nucleoside-diphosphate kinase MeSH D08.811.913.696.650.575 – nucleoside-phosphate kinase MeSH D08.811.913.696.900 – transferases (other substituted phosphate groups) MeSH D08.811.913.696.900.074 – CDP-diacylglycerol—inositol 3-phosphatidyltransferase MeSH D08.811.913.696.900.150 – CDP-diacylglycerol—serine O-phosphatidyltransferase MeSH D08.811.913.696.900.200 – diacylglycerol cholinephosphotransferase MeSH D08.811.913.696.900.250 – ethanolaminephosphotransferase
== Organization == By NIGMS program mandate, Glue Grant consortia must contain core resources and bridging projects. The EFI consists of six scientific cores which provide bioinformatic, structural, computational, and data management expertise to facilitate functional predictions for enzymes of unknown function targeted by the EFI. At the beginning of the grant, these predictions were tested by five Bridging Projects representing the amidohydrolase, enolase, GST, HAD, and isoprenoid synthase enzyme superfamilies. Three Bridging Projects now remain. In addition, the Anaerobic Enzymology Pilot Project was added in 2014 to explore the Radical SAM superfamily and Glycyl Radical Enzyme superfamily.
Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. Its chemical formula is (C2H2F2)n. PVDF is a specialty plastic used in applications requiring the highest purity, as well as resistance to solvents, acids and hydrocarbons. PVDF has a lower density of 1.78 g/cm3 in comparison to other fluoropolymers, like polytetrafluoroethylene. It is available in the form of piping products, sheet, tubing, films, plate and an insulator for premium wire. It can be injected, molded or welded and is commonly used in the chemical, semiconductor, medical and defense industries, as well as in lithium-ion batteries. It is also available as a cross-linked closed-cell foam, used increasingly in aviation and aerospace applications, and as an exotic 3D printer filament. It can also be used in repeated contact with food products, as it is FDA-compliant and non-toxic below its degradation temperature. As a fine powder grade, it is an ingredient in high-end paints for metals. These PVDF paints have extremely good gloss and color retention. They are in use on many prominent buildings around the world, such as the Petronas Towers in Malaysia and Taipei 101 in Taiwan, as well as on commercial and residential metal roofing. In biotechnology, PVDF membranes are used to immobilize proteins for a western blot. PVDF is also used as a binder component for the carbon electrode in supercapacitors and for other electrochemical applications.
== U == UbiD protein domain - ubiquitin—calmodulin ligase - UDP-3-O-N-acetylglucosamine deacetylase - UDP-4-amino-4,6-dideoxy-N-acetyl-alpha-D-glucosamine transaminase - undecaprenyl-phosphate 4-deoxy-4-formamido-L-arabinose transferase - untranslated RNA - upstream - upstream activator sequence - upstream DNA - upstream (transduction) - uracil - uracil/thymine dehydrogenase - ureidoglycolate hydrolase -
Sources: en.wikipedia.org
==== Operation bootstrap (1948) ==== Operation Bootstrap was enacted in 1948 and was the result of Puerto Rico's desire to attract outside capital by inviting U.S. private funds. Therefore, a tax arrangement was made by the U.S. to improve the industrial production on the island in an effort to increase profits and funnel money to the mainland. This economic development program enticed industries within the U.S. that were in search of "cheap labor, tax exemptions, and free trade between Puerto Rico and the mainland". This rapid foreign investment provided promise for disadvantaged Puerto Rican women who were struggling to navigate through domestic working conditions and limited job opportunities. Operation Bootstrap was marketed and believed to be an advantageous new service sector for women in search of white collar jobs. However, Puerto Rican women and the vast majority of the island experienced the exact opposite. Operation Bootstrap resulted in "high unemployment, increased migration, exacerbated poverty", and most importantly, economic colonization.
Coomassie brilliant blue is the name of two similar triphenylmethane dyes that were developed for use in the textile industry but are now commonly used for staining proteins in analytical biochemistry. Coomassie brilliant blue G-250 differs from Coomassie brilliant blue R-250 by the addition of two methyl groups. The name "Coomassie" is a registered trademark of Imperial Chemical Industries.
==== Adrenocortical carcinoma and tumors ==== Adrenocortical carcinoma occurs rarely; the average incidence rate is estimated to be 1–2 cases per million annually. The disease involves the formation of cancerous cells within the cortex of one or both of the adrenal glands. Although these tumors are identified in fewer than two percent of patients diagnosed with hyperandrogenism, the possibility must be considered within this population. In one study, more than half of tumor-affected patients had elevated levels of the androgens androstenedione, dehydroepiandrosterone sulfate, and testosterone. The elevation of androgens caused by adrenocortical carcinomas often causes patients to develop Cushing's syndrome, primary aldosteronism, and hyperandrogenism. The molecular basis of the disease has yet to be elucidated.
=== EC 1.5.8 With a flavin or flavoprotein as acceptor === EC 1.5.8.1: dimethylamine dehydrogenase EC 1.5.8.2: trimethylamine dehydrogenase EC 1.5.8.3: sarcosine dehydrogenase EC 1.5.8.4: dimethylglycine dehydrogenase
Sources: en.wikipedia.org
It is a set of checks performed before or during an HPLC run to confirm the system works as expected. Parameters may include resolution, tailing factor, theoretical plates, and retention time precision. Failure can trigger maintenance, method adjustment, or repeat analysis.
Validation follows a planned protocol that tests accuracy, precision, specificity, linearity, range, detection limits, quantitation limits, and robustness. Results are compared against predefined acceptance criteria. The validation report supports regulatory filing or routine use.
Revalidation may be needed after changes to column chemistry, mobile phase, detection, sample preparation, or instrument type. It can also follow a pattern of out-of-specification results. The scope depends on whether the change affects method performance.
System suitability is a set of checks performed before and during an HPLC run to confirm that the instrument and method are working as expected. It may include retention time repeatability, resolution between peaks, peak symmetry, and signal intensity. Failing suitability criteria usually invalidates the run.