Single-cell PCR analysis of the housekeeping genec-raf-1 and the bcl-2/JH rearrangement by seminested PCR analysis of cells isolated from frozen sections of a case of t(14;18)/MBR-positive follicular lymphoma (FL). The amplified DNA was separated on 2% agarose/NuSieve gel electrophoresis and visualized by staining with ethidium bromide. Ø, molecular weight markers; BL (blank), PCR amplification without DNA template to rule out contamination; O, single-cell positive control: t(14;18)/MBR-positive OCI LY8 tumor (lanes O, bcl-2/JH: 1 and 2). Single-cell DNA has been successfully amplified using c-Raf-1 primers (lanes FL: c-raf-1: 1 through 5): 4 positive cells (lanes 1, 2, 4, and 5) and bcl-2/JH primers (lanes FL, bcl-2/JH: 1 through 5): 4 positive cells (lanes 1 and 3 through 5). As expected, the amplification of the c-Raf-1 gene shows a band of 180 bp and the amplification of the t(14;18)/MBR shows a rearranged bcl-2/JH band within the expected range of size (110 to 360 bp).
