PCR amplification of nucleotides 41 to 393 (lanes 3 and 6) and 309 to 655 (lanes 2 and 5) of neutrophil FcγRIIIB mRNA. The locations of the 2 primer pairs (arrows) used for PCR amplification of the expected 353- and 347-bp products after nested PCR are illustrated above. cDNA derived from a SH(−) (lanes 2 and 3) and a SH(+) individual (lanes 5 and 6) were amplified with primer pair no. 3 and no. 4 (lanes 3 and 6) or primer pair no. 5 and no. 6 (lanes 2 and 5) and analyzed on 1.5% agarose gel stained with ethidium bromide. PCR without template was run as negative control (lane 4). DNA size standards (pBr 328 DNA.BglI + pBr 328 DNA.HinfI) are shown in lane 1. The resulting 353-bp and 347-bp products from the SH(+) individual (lanes 5 and 6) were isolated from preparative gels and subcloned for nucleotide sequence analysis.