Chromosome Analysis, Sister Chromatid Exchange (SCE) for Bloom Syndrome, Blood
Method Description Describes how the test is performed and provides a method-specific reference
A portion of the whole blood is transferred to a flask containing media and a cell mitogen. The cells are incubated for 96 hours at 37 degrees C. Twenty-four hours before harvest the cells are exposed to bromodeoxyuridine (BrdU) and protected from light. In the harvest process, the cells are exposed to colcemid and a hypotonic solution, and fixed with glacial acetic acid and methanol. Metaphase cells are dropped onto microscope slide and are treated with acridine orange. Twenty metaphases are examined for sister chromatid exchange (SCE) using a fluorescence microscope system and documented by computer-based imaging. Mean frequency of SCE per metaphase is calculated and compared with SCE per metaphase from a parallel control.(Dicken CH, Dewald G, Gordon H: Sister chromatid exchanges in Bloom's syndrome. Arch Dermatol 1978;114:755-760)
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
Original specimen - 3 weeks Remaining cell pellet - Indefinitely
Performing Laboratory Location The location of the laboratory that performs the test