Detection of beta-thalassemia mutations by ASO hybridization of PCR amplified DNA with digoxigenin ddUTP labeled oligonucleotides.

A simple procedure for nonradioactive labeling of oligonucleotides has recently been developed (1). It consists of 3' end labeling of oligonucleotides with terminal transferase by incorporation of a single digoxigenin labeled dideoxy uridine triphosphate. We used these oligonucleotides for allele specific oligomer hybridization of polymerase chain reaction amplified DNA, followed by an enzyme-linked immunoassay and subsequent enzyme-catalyzed color reaction. We compared this procedure with the standard radioactive oligonucleotide hybridization technique through the detection of the most common Mediterranean beta-thalassemia mutations. This procedure was also used for the confirmation of a new mutation at position -87 (C----A) (2) of the beta-globin gene and for the subsequent family analysis.