About Granzyme A
Cytolytic T lymphocytes (CTL) and natural killer (NK) cells share the remarkable ability to recognize, bind, and lyse specific target cells. They are thought to protect their host by lysing cells bearing on their surface 'nonself' antigens, usually peptides or proteins resulting from infection by intracellular pathogens. The protein described here is a T cell- and natural killer cell-specific serine protease that may function as a common component necessary for lysis of target cells by cytotoxic T lymphocytes and natural killer cells. [provided by RefSeq, Jul 2008]

About Fluorescein
Fluorescein is an organic fluorophore first synthesized by Aldolf Bayer in 1871. FITC, an amine-reactive derivative, is also a commonly used name for this dye. It has an excitation peak at 494 nm and an emission peak at 512 nm.