Quantitate and monitor intracellular cathepsin-B activity over time in vitro. The Magic Red substrate in this assay fluoresces red upon cleavage by active cathepsin enzymes. Analyze the fluorescent signal using fluorescence microscopy or a fluorescence plate reader.

Go to Full Product Details


Magic Red Cathepsin-B Assay Kit
SKU: 937

Size: 25 Tests
Price:
Sale price$191


Bulk Order Magic Red Cathepsin-B Assay Kit

Elevated cathepsin enzyme activity in serum or the extracellular matrix can signify a number of pathological conditions. ICT’s Magic Red assay kits are used by researchers seeking to quantitate and monitor cathepsin activity in cultured cells and tissues. This assay kit detects cathepsin-B activity. To use Magic Red, add the substrate directly to the cell culture media, incubate, and analyze. Because it is 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, allowing researchers 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.
MR-RR2
Cathepsin B
592 nm / 628 nm
Fluorescence Plate Reader, Fluorescence Microscope
Cell culture
2-8°C
Domestic: Overnight Delivery; International: Priority Shipping
United States
  1. Prepare samples and controls
  2. Reconstitute Magic Red by adding DMSO.
  3. Dilute Magic Red 1:10 by adding diH2O.
  4. Add 20 µL Magic Red to each sample (~ 500 µL aliquot of cultured cells).
  5. Incubate while protected from light.
  6. Watch color start to develop within 15 minutes.
  7. If desired, label with additional stains, such as Hoechst, DAPI, or an antibody.
  8. If desired, fix cells.
  9. Analyze with a fluorescence microscope or fluorescence plate reader. Magic Red has an optimal excitation at 592 nm and emission at 628 nm.

If working with adherent cells, please see the manual for additional protocols.

Kit 937: 25 Tests
  • Magic Red Substrate (MR-RR2), 1 25 Test Vial, #6133
  • Hoechst 33342, 1 mL, #639
  • Acridine Orange, 0.5 mL, #6130
  • Kit Manual
  • Kit 938: 100 Tests
  • Magic Red Substrate (MR-RR2), 1 100 Test Vial, #6134
  • Hoechst 33342, 1 mL, #639
  • Acridine Orange, 0.5 mL, #6130
  • Kit Manual
  • Murakawa, T;Nakamura, T;Kawaguchi, K;Murayama, F;Zhao, N;Stasevich, TJ;Kimura, H;Fujita, N. A Drosophila toolkit for HA-tagged proteins unveils a block in autophagy flux in the last instar larval fat body. Development (Cambridge, England). 2022 March 15; doi: 10.1242/dev.200243. Abstract

    Huang, P;Cao, Q;Xu, M;Dong, XP. Lysosomal ATP Transporter SLC17A9 Controls Cell Viability via Regulating Cathepsin D. Cells. 2022 March 4; doi: 10.3390/cells11050887. Article

    Vargas, G;Cortés, O;Arias-Muñoz, E;Hernández, S;Cerda-Troncoso, C;Hernández, L;González, AE;Tatham, MH;Bustamante, HA;Retamal, C;Cancino, J;Varas-Godoy, M;Hay, RT;Rojas-Fernández, A;Cavieres, VA;Burgos, PV. Negative Modulation of Macroautophagy by Stabilized HERPUD1 is Counteracted by an Increased ER-Lysosomal Network With Impact in Drug-Induced Stress Cell Survival. Frontiers in Cell and Developmental Biology. 2022 March 2; doi: 10.3389/fcell.2022.743287. Text

    Browning, CL;Green, A;Gray, EP;Hurt, R;Kane, AB. Manganese dioxide nanosheets induce mitochondrial toxicity in fish gill epithelial cells. Nanotoxicology. 2021 Jan 27; 1-18. doi: 10.1080/17435390.2021.1874562. Article

    Lan J, Luo H, Wu R, Wang J, Zhou B, Zhang Y, Jiang Y, Xu J. Internalization of HMGB1 (High Mobility Group Box 1) Promotes Angiogenesis in Endothelial Cells. Arterioscler Thromb Vasc Biol. 2020 Dec;40(12):2922-2940. doi: 10.1161/ATVBAHA.120.315151. Epub 2020 Oct 1. Full Text

    Jäger E, Murthy S, Schmidt C, Hahn M, Strobel S, Peters A, Stäubert C, Sungur P, Venus T, Geisler M, Radusheva V, Raps S, Rothe K, Scholz R, Jung S, Wagner S, Pierer M, Seifert O, Chang W, Estrela-Lopis I, Raulien N, Krohn K, Sträter N, Hoeppener S, Schöneberg T, Rossol M, Wagner U. Calcium-sensing receptor-mediated NLRP3 inflammasome response to calciprotein particles drives inflammation in rheumatoid arthritis. Nat Commun. 2020 Aug 25;11(1):4243. doi: 10.1038/s41467-020-17749-6. Full Text

    Yin Q, Jian Y, Xu M, Huang X, Wang N, Liu Z, Li Q, Li J, Zhou H, Xu L, Wang Y, Yang C. CDK4/6 regulate lysosome biogenesis through TFEB/TFE3. J Cell Biol. 2020 Aug 3;219(8):e201911036. doi: 10.1083/jcb.201911036. Full Text

    Almacellas E, Pelletier J, Day C, Ambrosio S, Tauler A, Mauvezin C. Lysosomal degradation ensures accurate chromosomal segregation to prevent chromosomal instability. Autophagy. 2020 Jun 23;1-18. doi: 10.1080/15548627.2020.1764727. Online ahead of print. Full Text

    Song SB, Hwang ES. High Levels of ROS Impair Lysosomal Acidity and Autophagy Flux in Glucose-Deprived Fibroblasts by Activating ATM and Erk Pathways. Biomolecules. 2020 May 13;10(5):761. doi: 10.3390/biom10050761. Abstract

    He M, Zhang T, Zhu Z, Qin S, Wang H, Zhao L, Zhang X, Hu J, Wen J, Cai H, Xin Q, Guo Q, Lin L, Zhou B, Zhang H, Xia G, Wang C. LSD1 contributes to programmed oocyte death by regulating the transcription of autophagy adaptor SQSTM1/p62. Aging Cell. 2020 Mar;19(3):e13102. doi: 10.1111/acel.13102. Epub 2020 Feb 19. Full Text

    Cannata Serio M, Graham LA, Ashikov A, Larsen LE, Raymond K, Timal S, Le Meur G, Ryan M, Czarnowska E, Jansen JC, He M, Ficicioglu C, Pichurin P, Hasadsri L, Ríos-Ocampo WA, Gilissen C, Rodenburg R, Jonker JW, Holleboom AG, Morava E, Veltman JA, Socha P, Stevens TH, Simons M, Lefeber DJ. sMutations in the V-ATPase assembly factor VMA21 cause a congenital disorder of glycosylation with autophagic liver disease. Hepatology. 2020 Mar 7. doi: 10.1002/hep.31218. [Epub ahead of print]. Abstract

    Kratschmer C, Levy M. Targeted Delivery of Auristatin Modified Toxins to Pancreatic Cancer Using Aptamers. Molecular Therapy-Nucleic Acids. 2017. 10:227-236 March 2018. doi.org/10.1016/j.omtn.2017.11.013. Full text

    Hover S, Foster B, Fontana J, Kohl A, Goldstein SAN, Barr JN, Mankouri J. Bunyavirus requirement for endosomal K+ reveals new roles of cellular ion channels during infection. PLoS Pathog. 2018. Jan 19;14(1):e1006845. doi: 10.1371/journal.ppat.1006845. eCollection 2018 Jan. Full text

    Festa BP, Chen Z, Berquez M, Debaix H, Tokonami N, Prange JA, Hoek GV, Alessio C, Raimondi A, Nevo N, Giles RH, Devuyst O, Luciani A. Impaired autophagy bridges lysosomal storage disease and epithelial dysfunction in the kidney. Nat Commun. 2018. Jan 11;9(1):161. doi: 10.1038/s41467-017-02536-7. Full text

    Qian Q, Zhang Z, Orwig, A, Chen S, Ding WX, Xu Y, Kunz RC, Lind NRL, Stamler JS, Yang L. S-nitrosoglutathione Reductase Dysfunction Contributes to Obesity-Associated Hepatic Insulin Resistance via Regulating Autophagy. Diabetes. 2017. Oct 26. pii: db170223. doi: 10.2337/db17-0223. [Epub ahead of print]. Abstract

    Chen J, Ou Y, Li Y, Hu S, Shao LW, Liu Y. Metformin extends C. elegans lifespan through lysosomal pathway. Elife. 2017.Oct 13;6. pii: e31268. doi: 10.7554/eLife.31268. Full Text

    Ríos-Luci C, García-Alonso S, Díaz-Rodríguez E, Nadal-Serrano M, Arribas J, Ocaña A, Pandiella A. Resistance to the antibody-drug conjugate T-DM1 is based in a reduction in lysosomal proteolytic activity. Cancer Res. 2017 Jul 7. doi: 10.1158/0008-5472.CAN-16-3127. [Epub ahead of print]. Abstract.

    Kang HT, Park JT, Choi K, Kim Y, Choi HJC, Jung CW, Lee YS, Chul Park S. Chemical screening identifies ATM as a target for alleviating senescence. Nat Chem Biol. 2017. Jun;13(6):616-623. Epub 2017 Mar 27. Abstract.

    Sakamaki JI, Wilkinson S, Hahn M, Tasdemir N, O’Prey J, Clark W, Hedley A, Nixon C, Long JS, New M, Van Acker T, Tooze SA, Lowe SW, Dikic I, and Ryan KM. Bromodomain Protein BRD4 Is a Transcriptional Repressor of Autophagy and Lysosomal Function. Mol. Cell. 2017. May 18;66(4):517-532.e9. doi: 10.1016/j.molcel.2017.04.027. Full text.

    Hamanaka T, Nishizawa K, Sakasegawa Y, Oguma A, Teruya K, Kurahashi H, Hara H, Sakaguchi S, Doh-Ura K. Melanin or melanin-like substance interacts with the N-terminal portion of prion protein and inhibits abnormal prion protein formation in prion-infected cells. J Virol. 2017. Abstract.

    Fujita N, Huang W, Lin TH, Groulx JF, Jean S, Nguyen J, Kuchitsu Y, Koyama-Honda I, Mizushima N, Fukuda M, Kiger AA. Genetic screen in Drosophila muscle identifies autophagy-mediated T-tubule remodeling and a Rab2 role in autophagy. Elife. 2017. Full text.

    Question: When you dilute the stock concentration 1/10 in H2O and aliquot is for future use, how long can this be stored? I see that the stock concentration in DMSO can be stored for 6 months.

    Answer: Once the stock solution is diluted 1:10 in diH2O we recommend using within 15 minutes to prevent hydrolysis of the Magic Red substrate. Non-specific hydrolysis would lead to fluorescence not associated with enzymatic cleavage of the substrate. We do not recommend attempting to aliquot or store the diH2O-diluted substrate solution for future use. Yes, that’s correct. The DMSO-reconstituted Magic Red stock can be stored frozen for up to 6 months protected from light and thawed more than twice during that time.

    Related Products

    Recently viewed