In OmniRat and OmniFlic, endogenous expression of rat immunoglobulin genes was inactivated using transient expression of a zinc-finger nucleases in single-cell rat embryos. IgM, IgG, IgE and IgA analyses demonstrated no detectable levels of rat Ig in our homozygous knockout animals. This important breakthrough was featured in the journal Science in July 2009.
OmniRat produces a diverse repertoire of antibodies with human idiotypes and similar immunological characteristics as rat antibodies from wildtype animals. As published in Journal of Immunology and Journal of Immunological Methods in 2013 OMT and Pfizer scientists have demonstrated that OmniRat:
OmniFlic is a rat with a single rearranged VkJk light chain and the same heavy chain transgene as OmniRat. Antibodies from OmniFlic comprise a single germline Vk sequence and can be generated through comprehensive analysis of the heavy chain repertoires without any use of hybridoma technology. OmniFlic and OmniClic both express the VK3-15 light chain and hence, antibodies generated using these platforms, can be combined to form a bi-specific antibody.
OmniMouse was engineered with the same transgenes as OmniRat. Unlike some other transgenic mice on the market and in development, OmniMouse has clear freedom to operate. OmniMouse expands the epitope coverage of OmniRat and creates the potential for even broader antibody discovery of single antibodies or antibody cocktails.