DGGE analysis of IgH CDR3 PCR products from microdissected marginal zones and adjacent germinal centers. Lanes 1 to 4, lanes 5 to 10, lanes 11 to 14, and lanes 15 to 18 represent cases 4, 1, 5, and 7, respectively. The even and odd numbers represent the analysis of the marginal zones and adjacent germinal centers, respectively. Two patterns are observed: a smear indicating polyclonal IgH rearrangements in lanes 6, 7, 8, 10, and 12; and a pattern with one or multiple bands indicating clonal IgH rearrangements in lanes 1 to 5, 9, 11, and 13 to 18. The analysis of the IgH CDR3 PCR products from Ki67-expressing marginal zones are observed in lanes 2, 4, 6, and 10.