RT-PCR analysis of murine perforin and granzyme B expression in Matrigel plugs. mRNA was prepared from Matrigel plugs impregnated with bFGF alone, bFGF + IL-12, bFGF + antiasialo GM1 antibody, or bFGF + IL-12 + antiasialo GM1 antibody, reverse-transcribed, and subjected to PCR amplification using specific primers for murine perforin and granzyme B. The amplified products were electrophoresed through a 1.5% agarose gel.