Reverse transcription-PCR analysis of EBNA-2 and LMP-1 mRNA expression in Jurkat cells (lane 1 and 4), NK-YS cells (lane 2 and 5), and LAD cells (lane 3 and 6). Ten microliters of reaction solution was applied to each lane of gel. The LAD cells expressed both EBNA-2 (195 bp) and LMP-1 (160 bp) mRNA. NK-YS cells expressed a low level of LMP-1 (130 bp) mRNA with about 30 bp deletion, but no EBNA-2 mRNA. ø X174 HaeIII digest was electrophorased in the MW lane.