Coupling of a DNA piezoelectric biosensor and polymerase chain reaction to detect apolipoprotein E polymorphisms.
In this paper we report the coupling of the Polymerase Chain Reaction (PCR) with a piezoelectric biosensor to detect a point mutation in a human gene. Biotinylated 23-mer probes were immobilised on the streptavidin coated gold surface of a quartz crystal; streptavidin was covalently bound to the thiol/dextran modified gold surface. The hybridisation of the immobilised probes with a short sequence (23 mer) complementary, non-complementary and mismatched DNA was investigated: the device was able to distinguish the different synthetic oligonucleotides. Many cycles of measurements can be performed on the same crystal surface regenerating the single strand of DNA with 1 mM of HCl. The same hybridisation reaction was then performed using real samples of human DNA extracted from blood and amplified by PCR, following a standard procedure for genetic detection of the polymorphism of the apolipoprotein E (apoE) gene. The procedure was able to distinguish the sequences present in the different samples, which differ only in one base: in this way it was possible distinguish between different groups of genotypes with apoE typing. Experiments with 'blank' samples confirmed the absence of adsorption or non-specific effects on the quartz crystal treated with the reported procedure.
Tombelli
S
S
Dipartimento di Sanità Publica, Epidemiologia e Chimica Analitica Ambientale, Università degli Studi di Firenze, Italy.
Mascini
M
M
Braccini
L
L
Anichini
M
M
Turner
A P
AP
D001057:Apolipoproteins E / Q000235:genetics*; D015374:Biosensing Techniques; D006801:Humans; D009693:Nucleic Acid Hybridization; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic
D001057:Apolipoproteins E