ROS1 with Interpretation by Immunohistochemistry with Reflex to FISH if Equivocal or Positive
Ordering Recommendation

Determine eligibility for tyrosine kinase inhibitor (TKI) (eg, crizotinib) therapy, primarily in individuals with pulmonary adenocarcinomas. Detects ROS1 fusion proteins (IHC) and ROS1 gene rearrangements (FISH).

1-5 days
Reflexed: Add 5-8 days
New York DOH Approval Status
This test is New York DOH approved.
Submit With Order
Immunohistochemistry Stain Form Recommended  (ARUP form #32978)Immunohistochemistry Stain Form Recommended (ARUP form #32978)
ARUP Consult®
Disease Topics
Specimen Required
Patient Preparation
Tumor tissue 
Specimen Preparation
Formalin fix (10 percent neutral buffered formalin) and paraffin embed tissue. Transport tissue block or 6 unstained (3- to 5-micron thick sections), positively charged slides in a tissue transport kit (ARUP supply #47808) available online through eSupply using ARUP Connect or contact ARUP Client Services at (800)522-2787. (Min: 6 slides) If sending precut slides, do not oven bake. 
Storage/Transport Temperature
Room temperature or refrigerated. Ship in cooled container during summer months. 
Unacceptable Conditions
Paraffin block with no tumor tissue remaining. Specimens fixed in any other fixative other than 10 percent neutral buffered formalin. Cytology specimens fixed in alcohol. Decalcified specimens. 
Include pathology report. IMMUNOHISTOCHEMISTRY ORDERING AND SUBMISSION DETAILS: Submit electronic request. If you do not have electronic ordering capability, use an ARUP Immunohistochemistry form (#32978) with an ARUP client number. For additional technical details, please contact ARUP Client Services at (800) 522-2787. 
Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable 
Reference Interval
Interpretive Data
Refer to report.

If ROS1by Immunohistochemistry result is equivocal or positive, then ROS1 by FISH will be added. Additional charges apply.
Hotline History
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CPT Code(s)
Component Test Code*Component Chart NameLOINC
2008415ROS1 by IHC Result
2008417ROS1 Client Block ID
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please view this test within the Laboratory Test Directory found at
  • ROS1 IHC
  • ROS1 IHC with Interpretation
  • ROS1 immunostaining