Expression of Rab27a and Rab27b in mouse tissues and melanocyte cell lines. Rab27a and Rab27b specific primers were used to amplify fragments of 445 bp and 550 bp respectively from the indicated mouse tissues (A) and melanocyte cell lines (B), as described in Materials and Methods. The PCR products were analysed on an agarose gel stained with ethidium bromide. The arrows on the left-hand side of the figure indicate positions of DNA marker sizes. Hprt was used as an internal control. Reaction performed without reverse transcriptase did not produce any detectable product.