FISH Study: X/Y Interphase (Bone Marrow)

Additional Information:

UFHPL Test #: 30280

UFHPL Epic order code: LAB5851

CPT Code(s):

  • 88271
  • 88275
  • 88291

Specimen Requirements:

  • Bone Marrow Aspirate: Obtain 1 – 2 cc of in a green-top sodium heparin tube and immediately rotate it thoroughly to ensure adequate mixing with the anticoagulant.
  • Bone Marrow Core Biopsy: Deposit samples in a sterile container containing tissue culture medium with antibiotics (RPMI) that have been brought to room temperature before collection.*
  • Peripheral Blood Specimens: Peripheral blood specimens may be submitted in certain clinical conditions if warranted.
Unacceptable Conditions:
  • Frozen specimens
  • Specimens for FISH study only > one week old
  • Specimens for concurrent FISH and cytogenetic studies > 48 hours old*
  • Formalin, alcohol or paraffin-preserved specimens
Stability (collection to initiation of testing):
  • Ambient: 24 – 48 hours*
  • Frozen: Unacceptable

Do not freeze or fix samples in any manner contrary to the maintenance of cell viability. Maintain sample sterility; keep all specimens at room temperature; and deliver samples to the laboratory within 24 – 48 hours. Ship specimens at room temperature for overnight delivery.

* Cell viability of specimens requiring cell culture may be compromised in specimens older than 48 hours upon receipt. Refrigeration at 2° – 8° C may assist when a delay is not preventable. Do not freeze or place specimens directly on ice.


This test is used to monitor sex-mismatched bone marrow and/or stem-cell transplantation status.


Interphase nuclei fluorescence in-situ hybridization (FISH) copy number analyses; a concurrent or previous conventional cytogenetic workup is required/recommended (where possible)


5 – 12 days

Reference Values:

By report; interpretive