HER2 Amplification Associated with Gastroesophageal Cancer, FISH, Tissue
Method Description Describes how the test is performed and provides a method-specific reference
The test uses the dual-color PathVysion HER2 DNA probe set (Abbott Molecular) with a HER2 probe and a chromosome 17 centromere probe (CEP17; D17Z1). Paraffin-embedded tissues are cut at 5 microns and mounted on positively charged glass slides. Four slides are prepared, with 1 slide stained with hematoxylin and eosin (H and E). The selection of tissue and the identification of target areas on the H and E-stained slide is performed by a pathologist. Using the H and E slide as a reference, target areas are etched with a diamond-tipped etcher on the back of the unstained slide to be assayed. The probe set is hybridized to the appropriate target areas and 2 technologists analyze 30 interphase nuclei each (60 total) with the results expressed as the average ratio of HER2 signals as compared to D17Z1 signals. A HER2:CEP17 ratio >2.2 indicates HER2 amplification, a HER2:CEP17 ratio of 1.8 to 2.2 is considered equivocal, and HER2:CEP17 ratio of <1.8 is considered not amplified. (Unpublished Mayo method)
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.
Samples processed Monday through Sunday. Results reported Monday through Friday, 8 a.m.-5 p.m. CST.
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