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Test ID: POC    
Chromosome Analysis, Autopsy, Products of Conception, or Stillbirth

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

Autopsy:

The specimen is cleaned and cut into small pieces and treated with enzymes. The tissue is then placed into a dish with a coverslip. Cells are cultured with Chang and MEM-alpha-medium containing 20% fetal bovine serum and antibiotics to establish a fibroblast culture. After 5 to 14 days, the fibroblasts are exposed to colcemid, ethidium bromide, 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 for structural and numeric chromosome abnormalities. 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)

 

Products of Conception or Stillbirth:

Fetal versus maternal tissue is identified whenever possible. This tissue is cut into small pieces and treated with enzymes. The tissue is then placed into a Petri dish with a coverslip. Cells are cultured with Chang and MEM-alpha-medium containing 20% fetal bovine serum and antibiotics to establish a fibroblast culture. After 5 to 14 days, the fibroblasts are exposed to colcemid, ethidium bromide, 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 tissues. In Current Methods of Autopsy Practice. Second edition. Edited by J Ludwig. Philadelphia, WB Saunders Company, 1979, pp 155-159; Spurbeck JL, Carlson RO, Allen JE, Dewald GW: Culturing and robotic harvesting of bone marrow, lymph nodes, peripheral blood, fibroblasts, and solid tumors with in situ techniques. Cancer Genet Cytogenet 1988;32:59-66; Lindor NM, Ney JA, Gaffey TA, et al: A genetic review of complete and partial hydatidiform moles and nonmolar triploidy. Mayo Clin Proc 1992;67:791-799)

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

No

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.

21 days

Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result

22 days

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

Any identifiable fetal tissue (e.g. skin, muscle) is held for 4 weeks. All other tissue (e.g. placenta, chorionic villus) are discarded at the time results are reported. If a pellet remains after testing it is stored indefinitely.

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

Rochester