Hoechst profile of YS and embryonic tissues isolated 8.0 dpc to 14.5 dpc. (A) A Hoechst SP is present in YS isolated 8.0 to 11.5 dpc and in embryonic tissues isolated 8.0 dpc to 14.5 dpc. Accompanying forward scatter/side scatter (FS/SS) profiles indicate distribution of all events in the Hoechst profile. (B) Gated SP demonstrates homogeneity by FS/SS distribution.