Biotinylated anti-mouse primary antibodies are immunoglobulins that directly bind specific mouse antigens (e.g., CD3, CD4, CD8, CD90, F4/80) and carry a covalently attached biotin moiety (vitamin B7, 244 Da). Unlike biotinylated secondary antibodies, which recognize mouse immunoglobulins, biotinylated primary antibodies enable single-step staining followed by streptavidin-based detection, eliminating the need for a secondary reagent.

The biotin label serves as a high-affinity handle for streptavidin- or avidin-conjugated reporters, exploiting one of the strongest non-covalent interactions known in biology (Kd ≈ 10⁻¹⁵ M). This system provides signal amplification, as multiple streptavidin-reporter molecules can bind each biotinylated antibody, enabling sensitive detection of mouse antigens. Biotinylated primary antibodies are particularly valuable in panels where secondary reagents must be avoided, such as in multiplexed flow cytometry or in applications requiring minimal background from endogenous immunoglobulins.

Applications

Flow Cytometry and Cell Sorting. Used with streptavidin-fluorophore conjugates (e.g., streptavidin-PE, streptavidin-APC) for immunophenotyping of mouse leukocyte subsets. 

Immunohistochemistry and Immunocytochemistry. Biotinylated primary antibodies enable signal amplification in labeled streptavidin-biotin (LSAB) systems. Biotin anti-mouse CD90 (clone 30-H12) is validated for flow cytometry and immunohistochemistry. 

Western Blotting. Used with streptavidin-HRP and chemiluminescent substrates for detection of mouse proteins on membranes.

ELISA. Serve as detection reagents in sandwich ELISA formats for quantifying mouse analytes. 

Blocking and Functional Studies. Certain clones possess functional activity.