Cathepsin B Assay Kit (Magic Red)

Product details

Magic Red Cathepsin B Assay Kit is used to quantitate and monitor cathepsin B activity in cultured cells and tissues.

How the assay works
Magic Red Cathepsin B Assay Kit ab270772 uses a cell permeant Cathepsin B substrate that becomes fluorescent on cleavage by Cathepsin B.
Magic Red detection substrates utilize the photostable red fluorophore, cresyl violet. When bi-substituted via amide linkage to two cathepsin target peptide sequences, such as (leucine-arginine)2, the bi-substituted cresyl violet is non-fluorescent. Following enzymatic cleavage at one or both arginine (R) amide linkage sites, the mono and non-substituted cresyl violet fluorophores generate red fluorescence when excited at 550-590 nm. Our Magic Red cathepsin B substrate, MR-(RR)2, is comprised of cresyl violet coupled to two pairs of the amino acid sequence, arginine-arginine (RR), which is the preferential target sequence for cathepsin B.

Cathepsin B Assay Kit (Magic Red):
- add the substrate directly to the cell culture media, incubate, and analyze. Because it is a cell permeant, it easily penetrates the cell membrane and the membranes of the internal cellular organelles – no lysis or permeabilization steps are required.
- If cathepsin enzymes are active, the Magic Red substrate is cleaved and the cresyl violet fluorophore will become fluorescent upon excitation.
- As enzyme activity progresses and more Magic Red substrate is cleaved, the signal will intensify to watch the color develop over time.
- Samples can be analyzed by fluorescence microscopy or with a fluorescence plate reader. Hoechst 33342 and Acridine Orange are included in the kit to detect nuclear morphology and lysosomal organelle structure, respectively.

The staining solution is typically used to stain cells at approximately 1/25 for microscopy analysis or 1/15 for plate reader analysis.

How other researchers are using ab270772
Magic Red Cathepsin B Assay Kit has been used in variety of sample type including:
- Mouse embryonic fibroblasts 1
- Human Renal cell adenocarcinoma cell line 2
- Human neuroblastoma cell line 3
References: 1 - Wu J et al. 2023; 2 - Ferreira G et at 2022; 3 - Hu X et al. 2021.