mllGAAn microsatellite alleles in normal controls. Part of MLL intron 6 was amplified from normal DNA samples and separated on a denaturing PAGE gel (see Materials and Methods). Samples 1 through 3: Mother, father, and son, respectively, from a normal family showing inheritance of alleles. Samples 4 through 14: normal control samples. (a, b, and c) Designation of mllGAAn alleles. Faint bands above the main bands in lanes C1 through C7 are nondenatured PCR products.