T(11;18)(q21;q21)-positive gastrointestinal MALT lymphomas are heterogeneous with respect to the VH gene mutation status

Figure 1 Gel electrophoresis of PCR products from case 1, obtained with 6 primer sets amplifying the FR1-J_H region (A) and the FR3-J_H region (B). Experiments were performed in duplicate. For all amplifications, the reverse primer was J_H. A: The forward primers used are indicated on the gel. The agarose gel shows predominant bands with primer sets V_H3-J_H and V_H5-J_H; B: Polyacrylamide gel showing FR3-J_H amplicons of the same length starting from the V_H3-J_H PCR product (lanes 1, 2) and from the initial DNA sample (lanes 5, 6). No monoclonal FR3-J_H product was obtained starting from the V_H5-J_H PCR product (lanes 3, 4). These results indicate that the lymphoma cells use a V_H3 family gene and that the product obtained with the V_H5-J_H set is an unspecific product.