Quantitation of site-specific HPV 16 DNA methylation by pyrosequencing.

Human papillomavirus (HPV) is a necessary but insufficient cause of cervical cancer. Factors influencing transcription, such as epigenetic silencing through viral DNA methylation, may impact neoplastic progression. Pyrosequencing technology was applied to quantify methylation at 19 cytosine guanine dinucleotide (CpG) sites in the L1 3' and long control region (LCR) of HPV 16 DNA using cell lines, CaSki ( approximately 400 integrated copies of HPV 16) and SiHa (1-2 integrated copies of HPV 16) that differ in their transcriptional activity.

Human papillomavirus type 16 variant assignment by pyrosequencing.

Polymorphisms in human papillomavirus type 16 (HPV16) result in variants from the prototype sequence which can be designated according to geographic distribution and are broadly classified as European (E), African (Af), Asian (As), or Asian-American (AA). Detection of variants has been used to distinguish persistent HPV16 infection from re-infection in natural history studies, and variants have been associated with an increased risk of cervical disease in some populations. Variant determination usually relies on conventional Sanger sequencing of regions of the viral genome, with the major variant group assignments requiring the sequencing of only seven polymorphic sites spread over a 242-bp region of the E6 gene.

Detection and differentiation of Cryptosporidium parasites that are pathogenic for humans by real-time PCR.

Cryptosporidiosis is a significant cause of food-borne and waterborne outbreaks of diarrheal diseases. To better understand the route of transmission of Cryptosporidium parasites, a number of genotyping techniques have been developed, based on PCR-restriction fragment length polymorphism or sequencing analysis of antigen, structural, and housekeeping genes. In this study, a real-time assay for the detection of Cryptosporidium oocysts is described.