SiR-lysosome is based on the pepstatin A (a cathepsin D binding peptide) which has been labeled with the proprietary fluorophore silicon rhodamine (SiR). SiR is a bright and photostable rhodamine-like dye, but with advanced properties. SiR-lysosome is fluorogenic, cell permeable and highly specific for lysosomes. It stains lysosomes in live cells without the need for genetic manipulation or overexpression. Its emission in the far red minimizes phototoxicity and sample autofluorescence. SiR-lysosome is compatible with GFP and/or mCherry fluorescent proteins. It can be imaged with standard Cy5 filter sets. SiR-lysosome can be used for widefield, confocal, SIM or STED imaging in living cells and tissue. Probe quantity allows 50 – 200 staining experiments*.