Analysis of 2-amino acid swap mutants of MIP-1α and RANTES. Analysis of the 2-amino acid swap mutants in the CFU-A assay; wild-type muMIP-1α and RANTESQF and MIPAH were tested at 100 ng/mL, final concentration, for inhibitory activity in the CFU-A assay. In this assay, the average number of CFU-A colonies per control plate was 5.1 ± 1.2. As before, results are reported as a percentage of CFU-A colony growth plus or minus SEM. This assay is representative of 3 repeat assays.