The XM Factor is a potent blocker for eliminating endogenous mouse IgG in mouse tissues. It has been specially designed to work with Biocare’s Rabbit-on-Rodent and Goat Polymer detection systems. XM Factor cannot be used with Mouse-on-Mouse AP or HRP polymer. By adding XM Factor to the polymer detection, endogenous mouse IgG is dramatically reduced and/or is completely eliminated. Biocare has also developed Rodent Block M that blocks for nonspecific background staining, and at the same time, also helps reduce endogenous mouse IgG. The combination of Rodent Block M and the XM Factor provide clean staining for mouse tissue protocols. It can also be used on an automated staining system.