Test Catalog

Test ID: EXHD    
Hematologic Disorders, DNA Extract and Hold, Varies

Useful For Suggests clinical disorders or settings where the test may be helpful

Reserving nucleic acid on any specimen for which molecular analysis requiring DNA may be necessary at a future date, ensuring that adequate material for testing is available

Testing Algorithm Delineates situations when tests are added to the initial order. This includes reflex and additional tests.

DNA will be extracted from the specimen and stored at -80 degrees Celsius for 1 year from the date of the extraction process was performed. A report of "Performed" will be sent and a $50.00 processing fee will be assessed. To request molecular testing from the Molecular Hematopathology Laboratory's test menu, call 800-533-1710. Additional charges will be assessed for testing performed.

Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

It is frequently useful to obtain nucleic acid from clinical samples containing a hematopoietic neoplasm at the time of diagnosis, so that appropriate material is available for molecular analysis should subsequent testing be required. For example, when a diagnosis of acute myelogenous leukemia is made, there is a delay before karyotype information, which determines whether testing for molecular prognostic markers is necessary, is available. After this delay, the diagnostic sample is usually no longer available or the nucleic acid has degraded to such an extent that it is no longer adequate for testing. Thus, it is useful to obtain nucleic acid on such specimens promptly at diagnosis and retain it until it is known whether additional testing is necessary.

Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

Not applicable

Interpretation Provides information to assist in interpretation of the test results

A report of "Performed" will be sent and a $50 processing fee will be assessed. No interpretation will be given. Should the sample be used in future testing, interpretation would be incorporated with the final testing.

Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

The nucleic acid will be held at -80 degrees Celsius for 1 year from the time of extraction. The nucleic acid may only be used for suitable tests offered by the Molecular Hematopathology Laboratory at Mayo Clinic. Nucleic acid cannot be shipped to another institution for testing and cannot be released for research use.


Only liquid blood specimens will be processed. Paraffin-embedded material and fresh, solid tissue will not be accepted at this time.

Special Instructions Library of PDFs including pertinent information and forms related to the test