Northern blot analysis of hMLH1 gene transcript. Filters were hybridized with either hMLH1 probes (upper panel) or GAPDH probe (lower panel) as a control. (A) Lanes 1 through 9 are MegJ, P30OHK, BALL-1, MOLT4, MOLT16, CEM, Raji, THP1, and SKW3, respectively. (B) Lanes 1 through 12 show Ramos, Jurkat, HA, DND39, BALM1, ML1, KCL22, Ri-1, Daudi, HL60, RPMI8226, and TF1, respectively. A 2.7-kb transcript is detectable in all lanes except lane 2 of (A) and lane 7 of (B). No hMLH1 mRNA expression is found in P30OHK and KCL22.