Strategy for the identification of IgM, IgD, IgG, and IgA transcripts from single HCs.

Ten single tumor cells (FSC^hi/SSC^hi/CD11c⁺) from patient 103 were sorted on a FACS Vantage, and cDNA was prepared by means of random hexamers. A seminested (A, for IgM, IgD, IgG) or a nested (B, for IgA) PCR approach was used to identify each specific isotype transcript from individual HCs. Arrows indicate location of the primers used. Sequence and codon location for each primer are described in Table 1 and Thompsett et al11 (family 4–specific leader primer). FWR indicates framework region; CDR, complementary determining region; and C, constant region.