About Cystatin SN
The cystatin superfamily encompasses proteins that contain multiple cystatin-like sequences. Some of the members are active cysteine protease inhibitors, while others have lost or perhaps never acquired this inhibitory activity. There are three inhibitory families in the superfamily, including the type 1 cystatins (stefins), type 2 cystatins and the kininogens. The type 2 cystatin proteins are a class of cysteine proteinase inhibitors found in a variety of human fluids and secretions, where they appear to provide protective functions. The cystatin locus on chromosome 20 contains the majority of the type 2 cystatin genes and pseudogenes. This gene is located in the cystatin locus and encodes a cysteine proteinase inhibitor found in saliva, tears, urine, and seminal fluid. [provided by RefSeq, Jul 2008]

About Alexa Fluor 488
Alexa Fluor™ 488 (AF488, Alexa 488) has an excitation peak at 488 nm and an emission peak at 496 nm, and is considered a high-performance alternative to FITC. Alexa 488 is one of the most popular Alexa Fluor™ dyes and is widely used in Fluorescence Microscopy, flow cytometry, and for staining low expression markers. It is bright, highly photostable, resistant to pH changes, and less susceptible to photobleaching. Alexa 488 and is similar in size, brightness and application to DyLight™ 488, iFluor® 488 and CF®488A.