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BrdU detection

Cell proliferation can be monitored by detection of incorporated externally applied thymidine analogue BrdU (5-bromo-2-deoxyuridine) into freshly synthesized DNA. This BrdU-containing DNA is visualized using BrdU-specific antibodies. Similarly, freshly synthesized RNA can be visualized via incorporation and detection of externally applied BrU (5-bromouridine). Another thymidine analogue EdU (5-ethynyl-2-deoxyuridine) is being used to detect DNA synthesis by its labeling with fluorescent azides. Unlike BrdU, incorporated EdU forms interstrand crosslings in the DNA and induces apoptosis, whereas BrdU-labeled cells can be identified even after longer time still viable.

Most anti-BrdU antibodies (including Bu20a) crossreact with EdU, which makes the detection protocol more complicated, if both BrdU and EdU-containing cells need to be distinguished specifically and without high background. On the other hand, the mouse monoclonal antibody MoBu-1, specific for BrdU and BrU, is unique as it does not crossreact with EdU staining. It can thus be used to easily distinguish e.g. between sooner incorporated BrdU and later incorporated EdU, or between DNA synthesis (EdU) and RNA synthesis (BrU), without need to block non-specific EdU reactivity.

MoBu-1 (specific for BrdU and BrU; it does not crossreact with EdU): 11-286-C100
Bu20a (it detects BrdU and EdU): 11-682-C100, 1P-682-T100

Fig. 1: Immunohistochemistry staining of proliferating cells with incorporated BrdU on paraffin-embedded section of chick embryo using mouse monoclonal antibody MoBu-1.

  Fig. 2: Flow cytometry analysis of BrdU and BrU incorporation in CEM human acute lymphoblastic
leukemia cell line using mouse monoclonal antibody MoBu-1 and FITC-conjugated secondary antibody. The individual cell cycle phases (S-, G1-, G2/M-phase) are indicated in the figure.