Ethidium bromide-stained gels showing 174-bp male-specific product from PCR amplification of DNA from CD4⁺ and CD8⁺ cells purified from the blood of female animals A89163 and A91382 that had been transplanted with purified CD34⁺ Lin⁻ marrow cells from their male siblings. Positive controls, 10⁵ PBL from male baboon (lanes 1, 10, and 19); negative controls, 10⁵ PBL from female baboon (lane 15); water, no DNA, control (lanes 18 and 27); 100 CD8⁺ PBL from A89163 (lanes 2 through 5); 100 CD4⁺ PBL from A91382 (lanes 6 through 9); 10 CD8⁺ PBL from A89163 (lanes 11 through 14); 10 CD4⁺ PBL from A91382 (lanes 16 and 17); 10 CD4⁺ PBL from A91382 (lanes 20 through 22); 10 CD8⁺ PBL from A91382 (lanes 23 through 26). Lane M contains DNA molecular weight markers (molecular weight markers VIII; Boehringer Mannheim).