Spot analysis
Simple chemical test using drops on filter paper.
Wikipedia / Wikimedia Commons
Spot analysis, also called a spot test or spot test analysis, is a simple chemical technique that uses just a drop or two of a chemical solution, typically applied to a large piece of filter paper, with no need for complex instruments. Its development and widespread use are credited to Fritz Feigl. The term also describes a common test in microbiology.
In chemistry, Feigl’s work built on earlier research by Hugo Schiff—who published the first known spot test in 1859 for detecting uric acid—and on capillary analysis by Christian Friedrich Schönbein and Friedrich Goppelsröder. In 1952, the Chemical Society of Midland held a symposium for Feigl’s 70th birthday, drawing 500 scientists from 24 countries, where all main sessions focused on spot tests. The method relies on the visible colors of compounds to indicate chemical reactions, and it has since been adapted for modern quantitative techniques.
In microbiology, a spot assay or spot test checks the growth rate of bacteria or yeast on different media or performs serial dilutions of microbes. A 96-pinner, sometimes called a frogger, is often used for these tests. Spot assays also appear in high-throughput screening, such as monitoring the growth of mated cells or detecting protein-protein interactions in a yeast two-hybrid test, frequently with robotic assistance.
- field
- Chemistry, Microbiology
- known_for
- Development and popularization of spot analysis
- credited_developer
- Fritz Feigl
- earliest_publication
- Hugo Schiff's detection of uric acid in 1859
Lore & Background
The foundations of Feigl's work on spot analysis were the works of Hugo Schiff (the earliest publication about 'spot test' was Schiff's detection of uric acid in 1859) and of Christian Friedrich Schonberg and Friedrich Goppelsröder on capillary analysis. 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.
Reader's Guide
Spot analysis is significant as a simple and efficient technique that allows chemical assays to be performed with only a few drops of solution on filter paper, without sophisticated instrumentation. Its development and popularization by Fritz Feigl built upon earlier work by Hugo Schiff, Christian Friedrich Schonberg, and Friedrich Goppelsröder. The technique uses the qualitative characteristics of colored compounds to account for performed chemical reactions and has been used to develop new quantification methods using modern technology. In microbiology, a spot assay is used to check the growth rate of bacterial or yeast cells on different media or to perform serial dilution tests, often using a 96-pinner (frogger) or a robot for high-throughput screening. The 1952 symposium sponsored by the Chemical Society of Midland for Feigl's 70th birthday, attended by 500 scientists from 24 countries, underscores the international recognition of spot tests.
Did You Know?
- The earliest publication about a 'spot test' was Hugo Schiff's detection of uric acid in 1859.
- Fritz Feigl is credited with the development and popularization of spot analysis.
- A 1952 symposium for Feigl's 70th birthday was attended by 500 scientists from 24 countries.
- In microbiology, a 96-pinner (frogger) is often used to perform spot assays.
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