A laboratory exercise to determine human ABO blood type by noninvasive methods

Abstract

Analysis of single-nucleotide polymorphisms and their association with diseases and nondisease pheno-types is of growing importance in human biology studies. In this laboratory exercise, students determine the genetic basis for their ABO blood type; however, no blood is drawn. Students isolate genomic DNA from buccal mucosa cells that are present in saliva and analyze the DNA on an agarose gel. Subsequently, this DNA is used as a PCR template to amplify exons 6 and 7 of the gene that determines the human ABO phenotype. These PCR products are digested and run on agarose gels to examine the restriction fragment length polymorphisms. A deletion in the O1 allele converts the BestE II site in exon 6 into a Kpn I site, and this feature is used to determine the presence of O1 alleles. The pattern of exon 7 digest products allows students to distinguish among four other common ABO alleles: A1, A 2, B, and O2. This exercise introduces students to commonly used molecular biology techniques, such as genomic DNA isolation, PCR, gel electrophoresis, and restriction digests. © 2008 by The International Union of Biochemistry and Molecular Biology.