Assay
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An assay is a procedure in molecular biology for testing and/or measuring the activity of a drug or biochemical in an organism or organic sample.[1][2] A quantitative assay may also measure the amount of a substance in a sample. Bioassays and immunoassays are among the many varieties of specialized biochemical assays. Other assays measure processes such as enzyme activity, antigen capture, stem cell activity, and competitive protein binding.
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[edit] Assay varieties
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[edit] Cytotoxicity
A cytotoxicity assay measures how toxic a chemical compound is to cells.
- MTT assay
- SRB (Sulforhodamine B) assay
[edit] DNA
Assays for studying interactions of proteins with DNA include:
[edit] Protein
- Bicinchoninic acid assay (BCA assay)
- Bradford protein assay
- Lowry protein assay[3][4]
- Secretion assay
[edit] RNA
[edit] Cell counting
A cell-counting assay, may determine the number of living cells, the number of dead cells, or the ratio of one cell type to another. One example of a cell-counting assay is a blood cell count.
[edit] Petrochemistry
[edit] Virology
The HPCE-based viral titer assay uses a proprietary, high-performance capillary electrophoresis system to determine baculovirus titer.
The Trofile assay is used to determine HIV tropism.
One may use a viral plaque assay to calculate the number of viruses present in a sample. This technique requires counting the number of plaques formed by a virus sample, from which the actual virus concentration can be determined.
[edit] Cellular secretions
A wide range of cellular secretions (say, a specific antibody or cytokine) can be detected using the ELISA technique. The number of cells which secrete those particular substances can be determined using a related technique, the ELISPOT assay.
[edit] Drugs
[edit] See also
- Analytical chemistry
- CASY cell counting technology
- ELISA
- MELISA
- Multiplex (assay)
- Pharmaceutical chemistry
- Titration
[edit] References
- ^ The American Heritage Dictionary of the English Language. Fourth Edition. Houghton Mifflin Company: 2000.
- ^ McKean, Erin (ed.). The New Oxford American Dictionary. Second edition. Oxford University Press: 2005.
- ^ Lowry OH, Rosebrough NJ, Farr AL, Randall RJ (November 1951). "Protein measurement with the Folin phenol reagent". J. Biol. Chem. 193 (1): 265–75. PMID 14907713. http://www.jbc.org/cgi/pmidlookup?view=long&pmid=14907713.
- ^ http://www.animal.ufl.edu/hansen/protocols/LOWRY.htm
