The challenge is to determine which polymorphic sequences go together on which alleles, explained Erlich. In our research, we were able to successfully assign allele-level HLA genotypes at eight loci in 48 individual samples from the data produced in a single Genome Sequencer FLX System run. The abundance of long sequencing reads allowed us to unambiguously assign HLA alleles in a much faster and more cost efficient manner than with traditional technologies. We were also able to detect rare variants, such as the non-transmitted maternal allele in a SCIDS [Severe Combined Immunodeficiency Syndrome] sample, reflecting the presence of maternal cells in the subject ™s circulation.

This month, 454 Life Sciences will launch the latest GS FLX Titanium kits and software, offering increases in read length and throughput for amplicon sequencing. The new kits will improve targeting resequencing studies, such as HLA class I and II genotyping, by more completely covering loci with fewer amplicons and enhancing sensitivity for identifying rare variants and haplotypes. Our early work with the GS FLX Titanium amplicon sequencing kits have demonstrated that we can now type more individuals per run and more exons per amplification reaction, says Erlich.

As proven by this study, 454 Sequencing Systems provides a cost-effective and reliable alternative to current research methods for HLA typing, said Christopher McLeod, President and CEO of 454 Life Sciences. This will only improve with the longer read lengths available in our latest series of GS FLX Titanium kits and software.

SOURCE Roche