Zinc, a metallic chemical element, symbol Zn and atomic number 30 is chemically similar to Magnesium due to its similar size and sole oxidation state of 2+. Zinc is an essential mineral of great biological significance, because many enzymes require it as an essential cofactor. Examples of zinc's biological roles include signal transduction, gene expression, regulation of apoptosis, synaptic plasticity and prostate gland function. BioVision's Zinc Assay Kit is a convenient colorimetric assay in which Zinc binds to a ligand with development of absorbance at 560 nm. The assay can be used with biological samples such as serum, plasma, csf or urine with detection sensitivity 0.2 μg/ml (~1-3 μM).