Human Papillomavirus (HPV) Typing In Situ DNA Hybridization
Method Description Describes how the test is performed and provides a method-specific reference
The human papillomavirus (HPV) typing in situ DNA hybridization testing is based on colorimetric in situ hybridization techniques which detect the presence of nucleic acid in cells or tissues. Nucleic acid is visualized by hybridization of labeled DNA probes to target DNA in human tissue. Paraffin-embedded biopsies are sectioned and placed on positively-charged slides. One section is used for each probe set. The sections are deparaffinized, heat-treated, and digested proteolytically to expose the fixed target DNA. Labeled probe is then applied to the section. Double-stranded probe and target DNAs are simultaneously denatured to single strands by heating. The homologous sequences of probe and target then specifically anneal during the subsequent hybridization step. Hybridization probes are detected using a secondary biotinylated detection antibody followed by an alkaline-phosphatase conjugate (streptavidin) which binds specifically to the detection antibody. Dephosphorylation by alkaline phosphatase of the substrate 5-bromo-4-chloro-3-indolyphosphate in the presence of nitroblue tetrozolium results in the deposition of a purplish blue precipitate at sites of probe hybridization to HPV DNA. Finally, the sections are counterstained with nuclear fast red allowing for morphologic examination along with visualization of the target DNA. The test is capable of detecting 2 distinct groups of the virus: HPV 6/11 and HPV 16/18/31/33/35/39/45/51/52/56/58/66 in paraffin-embedded human anogenital tissue by in situ hybridization. (Jin L, Lloyd RV: In situ hybridization: methods and applications. J Clin Lab Anal 1997;11:2-9; Plummer TB, Sperry AC, Xu HS, Lloyd RV: In situ hybridization detection of low copy nucleic acid sequences using catalyzed reporter deposition and its usefulness in clinical human papillomavirus typing. Diagn Mol Pathol 1998;7:76-84; Sperry A, Jin L, Lloyd RV: Microwave treatment enhances detection of RNA and DNA by in situ hybridization. Diagn Mol Pathol 1996;5:291-296)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday; 9 a.m.
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded
Performing Laboratory Location The location of the laboratory that performs the test