HPV genotyping using the MyHPV chip test

The MyHPV chip test contains probes for 15 HR (HPV-16, -18, -31, -33, -35, -39, -45, -51, -52, -53, -56, -58, -59, -66, and -68) and 9 low-risk HPV types (HPV 6, 11, 34, 40, 42, 43, 44, 54, and 70). The MyHPV chip test was performed according to the manufacturer’s instructions under the supervision of Dr. A. Lee (pathologist with a specialty in gynecopathology and molecular pathology). The cervical DNA was isolated from specimens and amplified using polymerase chain reaction (PCR) with consensus GP5⁺/GP6⁺ primers. Beta-globin was amplified as an internal control. The PCR product (5 μL) was subjected to 2.5% agarose gel electrophoresis. Twenty-four type-specific 30-mer oligonucleotide probes containing an amine group at the 5' terminus were immobilized onto a slide glass chip. The PCR products were labelled with Cy5-dUTP, denatured, mixed with hybridization solution, and incubated on the DNA chip. The hybridized HPV DNA was visualized using a DNA chip scanner (ScanArray LITE, GSI Lumonics Inc., Bedford, MA, USA).

Clearly visualized double-positive spots for a specific HPV type were considered “specific HPV-positive.” Samples negative on the chip scanner but positive for the 150-bp HPV-specific band using gel electrophoresis were interpreted as “negative for 15 HR-HPV and nine low-risk HPV types but positive for other HPV types.” A lack of visualized spots and samples negative for the 150-bp HPV-specific band using gel electrophoresis were considered “HPV-negative.”