Simplified method of identifying severe combined immunodeficient (SCID) mice versus non-SCID mice by flow cytometric analysis of peripheral blood

Several studies have utilized simple breeding strategies to create new immunodeficient mouse strains from severe combined immunodeficient (SCID) mice and non-SCID mice with secondary traits in order to evaluate the involvement of lymphocytes and immune responses in a variety of processes. We utilized a breeding strategy with C.B- 17 scid/scid (SCID) (H-2(d)) mice and SJL (H-2(s)) mice to generate immunodeficient mice that were histocompatible with the inbred SJL strain (H-2(s)) in order to evaluate the role of histocompatible recipient lymphocytes in adoptively transferred autoimmune disease mediated by SJL T lymphocytes. [SCID x SJL]F1 mice (heterozygous for H-2 loci and heterozygous for the SCID mutation) were backcrossed with SCID mice and the resulting offspring expressed a variety of phenotypes, including SCID or non-SCID and H-2(s)/H-2(d) or H-2(d)/H-2(d). In order to screen offspring for the desired phenotype (SCID, H-2(s)), a flow cytometric method utilizing forward- and side-scatter parameters of peripheral blood cells was used to distinguish SCID from non-SCID animals. This method simplified the screening process and was as reliable as anti-CD3 fluorescent monoclonal antibody staining for detecting the presence (non-SCID) or absence (SCID) of T lymphocytes in peripheral blood.