PCR analysis of rearranged VH genes. Lymphoma DNA was amplified with six different VH leader primers and a consensus JH primer and the resultant products electrophoresed in 1.5% agarose and stained with ethidium bromide as shown in (A). Note the dominant band of the expected size (arrow) generated with the VH1-JH primer combination suggesting the lymphoma is using a VH1 family gene. To assess clonality, the VH PCR products and lymphoma DNA were further amplified with the FW3 and JH primers and the resultant products electrophoresed in 10% acrylamide and stained with ethidium bromide as shown in (B). Observe that the VH1 PCR products give a clonal band that comigrates with the clone in the lymphoma DNA (arrow), while the other PCR products give only polyclonal laders representing different sized V-D-J joints.