We have developed a MICA typing method based on polymerase chain reaction (PCR) sequence-based typing and a computer program that determines the polymorphisms and distinguishes the GCT repeats in exon 5. One PCR amplification was performed to obtain templates of 2.2 kb, including exons 2, 3, 4, and 5 of MICA to be sequenced with two forward and two reverse primers. Overlay of nucleotide sequencing signals resulting from presence of different GCT repeats in exon 5 from two different MICA alleles can be identified by a computer program that analyses the combined signal string containing the 35 bases.