A novel immunohistochemical detection system using mirror image complementary antibodies (MICA)

Aims: To describe and illustrate a novel and highly sensitive peroxidase-ba sed immunohistochemical detection system which employs mutually attractive, mirror image complementary antibodies (MICA). Methods and results: To demonstrate the sensitivity of the MICA system alon gside the avidin-biotin complex (ABC) method, we selected a range of mouse monoclonal and rabbit polyclonal primary antibodies against antigens that a re generally regarded as relatively difficult or impossible to detect on fo rmalin-fixed, paraffin-embedded lymphoid tissue. Compared with the ABC meth od, the MICA immunodetection method enabled us to dilute primary antibodies up to 200-fold with equivalent or superior immunostaining results and, usu ally, considerably shortened primary antibody incubation times. Conclusions: We have described and illustrated a novel immunohistochemical detection system and demonstrated greatly increased sensitivity over the co mmonly used ABC system. An additional advantage of the MICA system is that it is avidin-free and so avoids non-specific staining due to endogenous tis sue biotin.