Cysteine Assay Kit

Sample

Tissue extracts, Cell lysate, Cell culture media, Other biological fluids

Species Reactivity

Species-independent

Detection Method

Enzymes Assay

Intended Use

Detection and quantification of Cysteine content in tissue extracts, cell lysate, cell culture media, and other biological fluids samples.

Contents of Kit

Storage

2 - 8°C

Detection Range

20 mmol/L - 2000 mmol/L

General Description

Cysteine (CYS) is a sulfhydryl-containing amino acid and an important structural and functional part of proteins. In animals, cysteine is synthesized from transsulfuration of homocysteine, which is derived from the metabolism of the amino acid methionine. Cystathionine β-synthase catalyzes condensation of homocysteine with serine to form cystathionine, which is deaminated and hydrolyzed by Cystathionine β-lyase to form cysteine and α-ketobutyrate. Due to its nucleophilic nature, the thiol group of cysteine has numerous biological functions. The formation of disulfide linkages between the thiol groups of cysteine residues helps to stabilize the tertiary and quaternary structure of proteins. Cysteine, homocysteine (HCY), and other aminothiols exist in plasma in reduced, oxidized, and protein-bound forms, interacting with each other through redox pathways. Cysteine is the limiting precursor of the major intracellular antioxidant glutathione. The individuals with lower cysteine levels are more prone to damage from reactive oxygen species, which are generally removed either by thiols or by glutathione- linked enzymes. An elevated level of total cysteine also predicts adverse outcomes such as cardiovascular diseases and metabolic syndromes. Cysteine Microplate Assay Kit is a sensitive assay for determining Cysteine in various samples. Cysteine concentration is determined by sodium tungstate dihydrate. The reaction products can be measured at a colorimetric readout at 600 nm.