Figure 4.

PCR analyses of Human Splenic B cells and SKW 6.4 cell line after stimulations. A RT-PCR reaction was performed on cytoplasmic RNA isolated from the cells treated with the indicated stimulants. Three PCR primers, one forward and two reverse, were used to amplify the 3′ ends of the secretory and membrane Ig μ heavy chain mRNAs in the same reaction with [α-³²P]dCTP. The sec (412 nucleotides) and mb (386 nucleotides) Ig μ mRNA products were separated on a 5% acrylamide/8 M urea gel. The gel was dried and exposed to a PhosphorImager screen. The ratios of the sec:mb products were quantified, averaged with other similar determinations, and reported in Tables 1 and 2.