Chromosome Anomalies, Unspecified Miscellaneous with Chromosome-Specific FISH Probes
Method Description Describes how the test is performed and provides a method-specific reference
FISH using chromosome-specific paint probes (CSP), locus-specific probes, and/or alpha-satellite DNA probes that are labeled with fluorophores. The CSP utilizes a series of unique DNA sequences that covers a specific entire chromosome. Thus, there is a separate CSP probe for each individual chromosome. The central area of a centromere (kinetochore) consists of repetitive DNA (alpha-satellite) sequences. Since there is about a 10% difference in base-pair composition of each centromere, with very few exceptions alpha-satellite probes can be specific for particular chromosomes. Up to 5 additional metaphases or previously GTL-stained metaphases will be analyzed and photographed for CSP and/or alpha-satellite study. If mosaicism is suspected, more metaphases may be studied by FISH. Locus-specific DNA probes can be utilized to determine definitive deletions leading to a known syndrome or anomalous chromosome. In some instances, these deletions also can be utilized to determine the presence of deletion of this material in interphase cells, thereby eliminating the necessity of metaphase preparations.(Pinkel D, Straume T, Gray JW: Cytogenetic analysis using quantitative, high-sensitivity, fluorescence hybridization. Proc Natl Acad Sci USA 1986;83:2934-2938; Wullich B, Morgan R, Berger C, Sandberg A: Fluorescence in situ hybridization-a useful method in addition to routine cytogenetic techniques in neoplastic disorders. Appl Cytogenet 1990;16:1-4)
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
Performing Laboratory Location The location of the laboratory that performs the test