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Test Code LAB3489 Telomere Length

Important Note

Collect from Sunday 1100 - Thursday 1400 only. Deliver to Lab immediately.

Additional Codes


Clinical System Name

Telomere Length


Requests for telomere length measurements are typically from physicians curious to know whether the clinical problems of their patients could be related to cellular defects resulting from extremely short telomeres. Flow-FISH measurements have been shown to be valuable as a screening test for inherited telomere maintenance deficiencies resulting from mutations in dyskerin, telomerase RNA (hTERC), telomerase reverse transcriptase (hTERT) and other genes.

Sample Requirements

Specimen: Whole Blood

Container(s): Lavender/EDTA (Infants or Children) or Yellow/ACD (Adults)

Preferred Vol: See Below

  • Adults: 12.0 mL - 18.0 mL in Yellow/ACD
  • Infants and Children: 3.0 mL Minimum in Lavender/EDTA

Minimum Vol: See Above

Note: Sunday 1100 - Thursday 1400 collection only. Deliver to the Lab immediately. Keep specimens at room temperature. Receipt preferred within 24 hours of collection, but is acceptable up to 72 hours, especially in ACD tubes.


Samples will be rejected if blood tubes are not filled properly, if blood is received >72 hours
of collection or if blood was not stored at room temperature.

Processing Instructions

Reject due to:

Spin: N

Aliquot: N

Temp: RT

Storage Location: Affix large Epic label(s) to tube(s) and place in the room temperature Send Outs rack.


Off-site Collection: No off-site collection.


Specimen Type Temperature Time
Whole Blood Room Temp 48 h



N 3-4 w


Performing Laboratory

Johns Hopkins Genomics - MDL

1812 Ashland Ave, Room 245

Baltimore, MD 21205

Phone Number: (410) 955-8363


Department: Send Outs

Phone Number: (206) 987-2563

Reference Range

Interpretive report is provided.


Method: Flow Cytometry and Fluorescence in situ Hybridization (flowFISH)

Reports telomere length in peripheral blood lymphocytes and granulocytes.

Analytical Volume: See "Sample Requirements" section.


Send Out Instructions

Reference Test Name: Telomere Length Testing
Reference Test Number: None Specified

Must arrive within 48 hours of collection. Ship via FedEx Priority Overnight for delivery Tuesday through Friday.