SiR-Lysosome Kit

SiR-Lysosome Kit

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 – 300 staining experiments*. 


Optical properties

λabs    652 nm
λex      674 nm

εmax   1.0·105 mol-1·cm-1

MW     1237.7 g/mol

MF      C67H103N9O11Si



*Based on the following conditions: 0.3 – 1 ml staining solution / staining experiments with 0.5 – 1 µM probe concentration. The number of staining experiments can be further increased by reducing volume or probe concentration.

Cytoskeleton, Inc. is the exclusive provider of Spirochrome, Ltd. products in North America.


Live human fibroblast cells stained with 2 µM SiR-lysosome (red) and Hoechst (blue) for 1 h at 37°C and imaged by widefield microscopy and imaged by STED microscopy.


For product Datasheets and MSDSs please click on the PDF links below.

For comparison information with other nuclear stains click here.

AuthorTitleJournalYearArticle Link
Caire, Robin et al.YAP promotes cell-autonomous immune responses to tackle intracellular Staphylococcus aureus in vitroNature Communications 2022 13:12022ISSN 2041--1723
Scherer, Katharina M. et al.A fluorescent reporter system enables spatiotemporal analysis of host cell modification during herpes simplex virus-1 replication2021PMID 33380421
van der Welle, Reini E N et al.Neurodegenerative VPS41 variants inhibit HOPS function and mTORC1-dependent TFEB/TFE3 regulationEMBO molecular medicine2021ISSN 1757--4684
Özkan, Nazmiye et al.ER – lysosome contacts at a pre-axonal region regulate axonal lysosome availabilityNature Communications2021ISSN 2041-1723
Lu, Meng et al.Sea Cucumber-Derived Peptides Alleviate Oxidative Stress in Neuroblastoma Cells and Improve Survival in C. elegans Exposed to Neurotoxic ParaquatOxidative Medicine and Cellular Longevity2021ISSN 1942-0994
Matthias, Jessica et al.Cytoplasmic localization of prostate-specific membrane antigen inhibitors may confer advantages for targeted cancer therapiesCancer Research2021ISSN 1538-7445
Jongsma, Marlieke LM et al. SKIP ‐ HOPS recruits TBC 1D15 for a Rab7‐to‐Arl8b identity switch to control late endosome transport The EMBO Journal2020ISSN 0261--4189
Valenzuela, José Ignacio et al.Localized Intercellular Transfer of Ephrin-As by Trans-endocytosis Enables Long-Term SignalingDevelopmental Cell2020ISSN 1878-1551