Spot analysis, spot test analysis, or a spot test is a chemical test, a simple and efficient technique where analytic assays are executed in only one, or a few drops, of a chemical solution, preferably in a great piece of filter paper, without using any sophisticated instrumentation. The development and popularization of the test is credited to Fritz Feigl.[1][2]
Spot test or spot assay can also refer to a test often used in microbiology.
Chemistry
[edit]The foundations of Feigl's work on spot analysis were the works of Hugo Schiff (the earliest publication about "spot test" was Shiff's detection of uric acid in 1859[3]) and of Christian Friedrich Schonberg and Friedrich Goppelsröder on capillary analysis.[2]
On the occasion of Feigl's 70th birthday the Chemical Society of Midland sponsored a symposium in 1952, attended by 500 scientists from 24 countries, in which all plenary sessions were related to spot tests.[2]
The test uses the qualitative characteristics of colored compounds to account for performed chemical reactions. This technique has been used to develop new quantification methods using modern technology.[4]
Microbiology
[edit]
A spot assay or spot test can also refer to a specific test in microbiology. This test is often used to check the growth rate of bacterial or yeast cells on different media or to perform serial dilution tests of micro-organisms. Usually a 96-pinner (often called frogger) is used to perform these spot assay. Another application is high-throughput screening, whichoften uses spot assays to determine the growth of eg. mated cells or to check for protein-protein interactions in a yeast two-hybrid test. This is often done with a robot.[5]
See also
[edit]References
[edit]- ^ "Spot tests in organic analysis", numerous editions
- ^ a b c Espinola, Aida; da Silva Pinto, Mario A.; Costa Neto, Claudio (1995). "Fritz Feigl (1891-1971): The Centennial of a Researcher" (PDF). Bull. Hist. Chem. 17/18: 31–39.
- ^ H. Schiff, Ann. Chim. Acta, 1859, 109, 67.
- ^ Soares, Samara; Lima, Manoel J.A.; Rocha, Fábio R.P. (2017). "A spot test for iodine value determination in biodiesel based on digital images exploiting a smartphone". Microchemical Journal. 133: 195–199. doi:10.1016/j.microc.2017.03.029.
- ^ Thomas, Pious; Shekhar, Aparna C.; Upreti, Reshmi; Mujawar, Mohammad M.; Pasha, Sadiq S. (2015). "Optimization of single plate-serial dilution spotting (SP-SDS) with sample anchoring as an assured method for bacterial and yeast cfu enumeration and single colony isolation from diverse samples". Biotechnology Reports. 8: 45–55. doi:10.1016/j.btre.2015.08.003. PMC 4980700. PMID 28352572.