Magic Red Cathepsin B Detection Kit

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Trial size, ~25 tests:

Magic Red Cathepsin B Detection kit contains:
ICT's red Magic Red cathepsin B detection probe, MR-(RR)2
Hoechst stain (a blue DNA stain)
Acridine orange (a lysosomal stain)
MR-Cathepsins Manual

Some characteristics of cathepsin B:
1.  A endopeptidase with carboxydipeptidase activity.
2.  An abundant lysosomal protease like L and D.
3.  Associated with cancer malignancy.
4.  Involved in breakdown of proteins after phagocytosis and in subsequent antigen presentation.
5.  Requires an acidic environment for enzymatic activity.

ICT's Magic Red-RR kits measure active cathepsin B in whole living, intact cells - no lysis required. As cathepsin B activity increases, the red fluorescent signal increases. These unique kits are not ELISAs and do not use antibodies - instead they use a cell-permeant substrate sequence, RR, specifically targeted by active cathepsin B. This peptide sequence is linked to a red fluorophore, Magic Red, which fluoresces once cleaved by active cathepsin B. Only cells with active cathepsin B will fluoresce, so you dont get any signal from pro-enzymes or inactive forms of the enzyme. ICTs MR-RR kits give you a clear picture of cathepsin-B-positive versus negative cells.
     Cathepsin-B-positive cells often generate a signal 2-5x greater than the negative cell population when read in fluorescence plate readers. MR excites at 540-590 and emits at >610nm. This signal can be detected with a fluorescence microscope, a fluorescence plate reader, or special flow cytometers with adjustable excitation wavelengths.
     MR kits are very specific. However, there still can be some cross-reactivity as the reagent is incubating (often for several hours). ICT's Cathepsin B (MR-RR) reagent is the most specific of the cathepsin reagents - there is very little cross reactivity with other proteases. Cathepsin B is highly abundant and highly active.
     Cathepsin B is thought to be the most abundant cathepsin in the cell. It is lysosomal. After staining with MR, there are often areas of bright red fluorescence as the reagent is processed and concentrated within the lysosomal bodies.

Assess cathepsin B activity in vitro and in real time