Semkur-IM is a redox dye for easily assaying cell vitality in real-time.


  • Cell permeable and non-toxic
  • Negligible effect on GSH levels
  • Use with common fluorescent optics

Semkur-IM permeates live cells and fluoresces when the quenching component is cleaved off by cellular glutathione. Fluorescence intensity correlates with reduced glutathione (GSH) an indicator of cellular stress. The reduced/oxidized ratio (redox state) of glutathione typically exceeds 10:1 in healthy cells. Abnormal levels are associated with numerous pathologies including cancer, neurodegenerative diseases, cystic fibrosis, cardiovascular diseases, HIV and aging.

Catalog Number Product DataSheet Size AVAILABILITY Price Qty
1mg (10mM in DMSO) In stock
Regular Price:$265.00
On Sale:

Product Type: Small Molecule
Name: Semkur-IM
Alternative Name(s): DSSQ-1 probe
Molecular Weight: 792
Format: Liquid
Purity: 99% via HPLC
Buffer: DMSO
Ex/Em Maxima: 485-495/516-525
Platform: Microplate reader
Compatible Cells: NIH3T3 cells; cultured human cells; plasma; reacts blood components
Detection Method: Fluorescence
Comments: 1mg (sufficient for a 96 well plate)
Storage: Room temperature (powder); -20C resuspended
Shipped: Cold packs

From a laboratory at Vivid Microscopy.
The fluorescent probe is a di-thiol based indicator of oxidative stress. Data demonstrates penetration into the mitochondria; however, no penetration into the nuclear membrane. This was determined by co-localization studies. 
  1. Alvarez R, Kurfis J, Hendrickson M, Sem DS. Real-time thiol detection in iPSC-derived neuron cultures using SemKur-IM, a novel fluorescent dithio probe. SLAS Discov. 2023 Nov 20:S2472-5552(23)00081-3. doi: 10.1016/j.slasd.2023.11.003. Epub ahead of print. PMID: 38000947.
  2. Pullela PK, Chiku T, Carvan MJ and Sem D “Fluorescence-based detection of thiols in vitro and in vivo using dithiol probes” Analytical Biochemistry; 352 (2006) 265-273
  3. Chiku T, Pullela PK and Sem D “A Dithio-Coupled Kinase and ATPase Assay” Journal of Biomolecular Screening 11(7); 2006
  4. Tracy EP, Dukes M, Beare J, Rowe G, Nair R and LeBlanc AJ. Stromal Vascular Fraction Restores Vasodilatory Function by Reducing Oxidative Stress in Aging-Induced Coronary Microvascular Disease. Antioxid Redox Signal 2022 Aug 11. doi: 10.1089/ars.2021.0249. Online ahead of print

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