Chromosomes, Body Fluid
Method Description Describes how the test is performed and provides a method-specific reference
The tissue is centrifuged and the cell pellet is placed in culture medium. After 24 to 48 hours, the cultures may be harvested or a longer-term fibroblast culture may be established and harvested within 3 to 20 days or longer. The harvest procedure involves treating the cells with colcemid and hypotonic solution, and then fixing the cells with glacial acetic acid and methanol. Metaphase cells are dropped onto microscope slides and are routinely stained by G- or Q-banding. Twenty metaphases are usually examined. If a clone is suspected but not confirmed in 20 metaphases, an additional 10 cells will be analyzed. Minimal evidence for the presence of an abnormal clone is defined as 2 or more metaphases with the same structural abnormality or chromosome gain (trisomy), or 3 or more metaphases lacking the same chromosome. Five to 10 metaphases are captured using a computerized imaging system, and 1 or more karyograms from each clone are prepared to document the type of abnormality and to permit systematic interpretation of the anomalies. (Dewald GW, Hicks GA, Dines D, Gordon H: Usefulness of culture methods to aid cytogenetic analyses for the diagnosing of malignant pleural effusions. Mayo Clin Proc 1982;57:488-494)
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
Cell pellet: Indefinitely
Performing Laboratory Location The location of the laboratory that performs the test