Polymerase chain reaction of cells from the cerebrospinal fluid demonstrate lymphoma

The upper image (panel A) shows an ethidium bromide stained polyacrylamide gel electrophoresis photograph showing results of IgH gene rearrangement analysis for 3 CSF samples (marked 1, 2, 3) from the same patient with lymphomatous meningitis. Also shown is a negative control (N), a sample from a patient with infection (polyclonal, P), and a positive control (C). The bands seen for the patient's samples (arrows) and the positive control indicate PCR products spanning the hypervariable region of IgH. As the cells in the 3 patient specimens are clonally related, PCR products in the 3 assays are of identical length. By contrast, the polyclonal population in lane P gives rise to a smear (PCR products of variable length).
The lower image (panel B) shows the result of capillary electrophoresis of products generated through PCR using DNA isolated from a brain biopsy specimen of a patient with CNS dissemination from T cell lymphoma as a template. Primers spanned the hypervariable region of the gamma subunit of the T cell receptor gene. The 2 graphs of red and blue color represent PCR products of 2 parallel assays of the same specimen. X-axis: PCR product length in base pairs (bp); Y-axis: relative concentration of PCR product.