RT-PCR showed that hepG2 cells were positive for B7-1 at the messenger RNA(mRNA)level. The hepG2/Hb7-1 cell clone strongly expressing B7-1(positive rate:92.2%)was picked out.

• 而HepG2 /hB7 1的B7 1分子阳性表达率达到 92 6%25 ,转染B7 1基因后较转染前增大了 2 8倍多。