High throughput screening (HTS) is the process of testing chemical compounds and other substances to observe their interaction with biological materials. Laboratory equipment can screen many different samples at once, with the goal of finding a reaction to study further. The ultimate goal is to use reactive compounds to discover drugs for various diseases and conditions. Radioactive equipment was used in the past to detect reactions, but fluorescent techniques and systems are also used in the 21st century. Machines with higher capacities are also part of the process, so finding new pharmaceutical drugs becomes a quicker process.
The process of high throughput screening is centered on testing procedures, called assays, which measure how chemicals and drugs interact with organic material. One assay often used is a scintillation proximity assay, which uses radiation to track the behavior of molecules. Another type, time-resolved fluorescence, uses fluorescent particles to label other molecules and track their activity during reactions. Fluorescence polarization detects the rotation of molecules exposed to polarized light, and if less motion occurs, the nature of a reaction can be measured.
A job that involves compound evaluation requires skills in a variety of disciplines. Molecular biology education is essential because of the knowledge needed to understand the chemical and biological reactions. The ability to operate the various kinds of instrumentation, and an understanding of the analytical ability of computers, are also necessary. Each process must be fully understood, and a researcher has to also use his or her knowledge of the principles behind each one.
Various kinds of instruments are used in high throughput screening. Some can handle hundreds of thousands of tests each day. These tests sometimes yield useful results; other times results from metabolic and toxicity testing help identify compounds for further study. The equipment includes readers that can detect radioactive or luminescent molecules, and assay machines that can hold up to hundreds of samples at a time.
Compound evaluation is combined with finding a biological target for high throughput screening. This can be a specific enzyme, receptor, or chemical reaction that occurs in cells. Independent companies are often responsible for the testing, while pharmaceutical companies typically work in a partnership with them to develop drugs. Limitations of high throughput screening include the expenses of obtaining materials and equipment. The potential sale of new drugs, as well as the licensing of materials and procedures to other companies, helps to make HTC a profitable venture.