IgH electrophoretograms produced by gene scanning software of PCR-amplified DNA extracts from unprocessed BM and PBPC products and from various control samples. Lines 1 to 8, samples 21, 22, and 24 to 28 from BM of NHL patients. Lines 3 and 4 corresponded to BM samples of patient 24 collected at a 3-month interval. Line 9, control BM of a healthy donor (HD). Lines 10 to 18, samples 33 to 35, 37, 39, 41 to 43, and 45 from PBPC of NHL patients. Lines 19 to 26, control samples from various solid tumors. Line 27, control blood from a healthy donor (HD). Abnormal peaks are indicated by an arrow (➭). Please note that in the ethidium bromide staining technique, samples 21, 22, 24, 26, 27, 28, 33, 45 and the controls were found negative, while samples 25, 34, 35, 37, 39, 41, 42, and 43 were found positive.