Flow cytometric analysis of chimeric receptor expression in M1 transformants. M1 cells were transfected with GM-CSFR-LIFR and GM-CSFR βc-LIFR cDNA. The cells were incubated with anti–GM-CSFR  (B) or anti–GM-CSFR βc (C). Antibody binding was detected by incubation with fluorescein-conjugated rabbit antimouse immunoglobulin. Samples were analyzed using a flow cytometer. (A) The flow cytometry profile stained with the fluorescein-conjugated second antibody alone.