Detection and haplotype differentiation of Southeast Asian α-thalassemia using polymerase chain reaction and a piezoelectric biosensor immobilized with a single oligonucleotide probe

DNA-based diagnosis of α-thalassemias routinely relies on polymerase chain reaction (PCR) and gel electrophoresis. Here, we developed a new procedure for the detection and haplotype differentiation of Southeast Asian (SEA) α-thalassemia using a 3-primer system for PCR coupling with a DNA-based piezoelectric biosensor. PCR products amplified from genomic DNA were differentiated directly by using a quartz crystal microbalance immobilized with a single oligonucleotide probe. The frequency changes after hybridization of the PCR products amplified from a representative sample of normal α-globin, SEA α-thalassemia heterozygote, and homozygote were 206 ± 11, 256 ± 5, and 307 ± 3 Hz, respectively. The fabricated biosensor was evaluated through an examination of 18 blind specimens. It could accurately discriminate between normal and SEA α-thalassemic samples, which suggests that this biosensor system is a promising alternative technique to detect SEA α-thalassemia because of its specificity and less hazardous exposure as compared with conventional methods.