Test Catalog

Test ID: CHRTI    
Chromosome Analysis, Skin Biopsy

Method Description Describes how the test is performed and provides a method-specific reference

The specimen is cut into small pieces and treated with enzymes. The tissue is then placed into a tissue flask with Chang and MEM-alpha-medium containing 20% fetal bovine serum and antibiotics to establish a fibroblast culture. The fibroblasts are exposed to ethidium bromide, colcemid, and hypotonic solution, and fixed with glacial acetic acid and methanol. Metaphase cells are dropped onto microscope slides and are routinely stained by G-banding, but other staining methods are frequently employed as needed. At least 20 metaphases are examined. Minimal evidence for the presence of an abnormality 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 computer-based imaging system and karyograms are prepared from 2 or more representative metaphases.(Dewald GW: Chromosome study of autopsy tissue. In Current Methods of Autopsy Practice. Second edition. Edited by J Ludwig. Philadelphia, WB Saunders Company, 1979, pp 155-159)

PDF Report Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Friday

Report Available The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

23 to 24 days

Specimen Retention Time Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

Any remaining specime is discarded at the time results are reported.

Performing Laboratory Location Indicates the location of the laboratory that performs the test