Catalog # RM4931

Rb (deltaRb-p70), cleavage-specific Antibody

Mouse Monoclonal

Application / Dilution

Size 100 μl

Species Reactivity Hu, Rt, Ms

MW 106 kDa

Isotype IgG1



The retinoblastoma gene product (Rb) is a tumor suppressor protein that acts as cell cycle regulator and has roles in apoptosis. During apoptosis, Rb is subjected to cleavage by caspase-3 like protease. Caspase-3 cleaves Rb into 48 and 68kDa fragments. Cleavage of Rb would make it functionally inactive, causing release of E2F-1. The E2F-1 then may promote apoptosis. RM4931 mouse monoclonal antibody recognizes cleaved Rb (deltaRb-p70), but does not recognize full-length Rb. In camptothecin treated HL60, an ~68 kDa band is observed. deltaRb-p70 exists in vivo as an N-terminally truncated form of Rb. deltaRb-p70 is thought to be the product of alternative translation and is expressed in primary myeloid cells in fetal liver, bone marrow and spleen. DRb-p70 is also specifically expressed in tumor-associated macrophages (TAMs). TAMs are an important targets of cancer therapy. deltaRb-p70 is a marker of TAMs, and maybe useful for identifying tumors with macrophage infiltration.



An B. & Dou Q.P. (1996) Cancer Res. 56:438.
Dou Q.P. et al. (1997) J. Cell. Biochem. 64:586.
Fattman C.L. et al. (2001) Oncogene. 20:2918.

Western blot analysis of HL60 cells that were treated with camptothecin for 24 hours. The blot was probed with anti-Rb, cleavage-specific RM4931.

Clone 172C1094 was developed from a synthetic peptide corresponding to a region of the caspase-3-induced cleavage site of human Rb. The sequence is well conserved in rat and mouse Rb.

*For more information, see UniProt Accession P06400
Mouse monoclonal antibody purified with protein G chromatography is supplied in 100µl phosphate-buffered saline, 0.05% BSA, and 0.05% sodium azide. Store at 4°C. For long term storage, store at –20°C.

The products are are safely shipped at ambient temperature for both domestic and international shipments. Each product is guaranteed to match the specifications as indicated on the corresponding technical data sheet. Please store at -20C upon arrival for long term storage.

The antibody detects cleaved Rb (deltaRb-p70) at 68 kDa* in HL60 cells treated with camptothecin. The antibody does not detect full length Rb. RM4931 can be used for western blot and immunohistochemistry.

*All molecular weights (MW) are confirmed by comparison to Bio-Rad Rainbow Markers and to western blot mobilities of known proteins with similar MW.

This kit contains: