In laboratory medicine, mining, pharmacology, environmental biology, and molecular biology, an assay is a qualitative or quantitative method for assessing or quantifying the presence, amount, or functional activity of a target item. A drug, biological substance, chemical element or molecule, or cell in an organism or organic material can all be used as analytes. The analyte, measurand, or assay target are all terms used to describe the item that is being measured. The goal of an assay is to determine the intensive property of an analyte and express it in the appropriate measurement unit (e.g., molarity, density, functional activity in enzyme international units, degree of effect in comparison to a standard, etc.). Assay systems are procedures for determining the existence, amount, or activity of a material, such as a drug, cell type, or cell component. In assay systems, a variety of experimental procedures are employed to detect distinct components of organic samples.