Restriction analysis of the NA1-, NA2-, and SH-constructs. After PCR amplification of the NA1- (lanes 1), NA-2 (lanes 2), and SH-constructs (lanes 3), FcγRIIIb fragments encompassing nucleotides 41-393 were digested with NA-specific TaqI (left panel) or SH-specific SfaNI endonuclease (right panel) and were analyzed on 4% or 1.5% agarose gel, respectively.