The very first step of successful drug discovery and development is creating a test system known as an assay. These assays help in evaluating the chemical compound effects on molecular, biochemical, cellular processes of targets.
There are two main types of Assays in Drug Discovery
- Biochemical Assays (Target based)
- Cell-based Assays (Phenotype-based)
These are used as a regular and trustworthy procedure to help understand the biomolecular functions during drug development. The use of both the types of assays together is usually recommended to measure a pathway or target. A compound assessed through biochemical analysis may show high potency and may not show the same potency in cell-based assays.
On the other hand, as a result of medicinal optimization, a compound with high potency in a cell-based assay may reveal high potency in a biochemical assay as well. This can enhance the physicochemical properties of the compound. Hence for a successful optimization of compound, performing both assays is essential in drug development.
Biochemical assays. These enable the quantifying of metabolic activity and assist in measuring the functional behavior of biomolecules. These include enzymes, cofactors, proteins, and other small molecules. Biochemical assays can also help identify various
interactions such as protein-RNA, protein-protein, and protein-DNA.
The quality of a biochemical assay is defined by its robustness and its ability to reproduce the signals even in the absence of test compounds. The assay quality, as well as the quality of the data collected, largely influences the predictive biological analysis and a compound’s pharmacological activities. The assay quality determines data quality. Any compromise on assay development can hence have potentially negative consequences.
Critical considerations in the Development of Assays
The biomedical research investigators suggest ideas for such assays to the scientists, who develop these further for small molecule screening. The results obtained from these screens are called probes, which help researchers explore the biological processes, cell and protein functions, and the effects of chemicals that are significant to human health. These probes help in drug development by becoming potential therapeutic candidates.
Common Assay Formats
- Colorimetric or chromogenic
These reactions show a visible change in color.
- Fluorometric or fluorogenic
These reactions are based on excitation by a source of light and emit a fluorescent signal.
These reactions emit light upon a chemical reaction.
Importance of Assay Development
Proper biochemical assay development is essential for improving the effectiveness and safety profile of any drug development experiments. The development of biochemical assays is crucial for robust performance, high reproducibility, and a better serum tolerance.
A biochemical assay reliably measures the target of interest. A proper analysis method enables successful and scalable identification of targets, helps in the mitigation of risks, and expedites the journey of drug development from lab to the marketplace.