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Test Code FALKC ALK on Cytology Specimens, FISH

Useful For

Detection of rearrangements involving the ALK gene region at 2p23 in patients with non-small cell lung carcinoma who may benefit from treatment with the ALK inhibitor drugs, like Xalkori (Crizotinib), on previously stained routine cytology slides

Testing Algorithm

This assay can be utilized in clinical situations in which formalin-fixed, paraffin-embedded material is insufficient for the FDA-approved method.

Method Name

Fluorescence In Situ Hybridization (FISH) using DNA Probes

Reporting Name

ALK on Cytology Specimens, FISH

Specimen Type


Advisory Information

A quality specimen is essential for evaluation. A cytology slide less than 10 years in age and containing ≥100 non-overlapping tumor cells within an 18-mm area should meet quality standards.

Specimen Required

Submit a previously stained and cover slipped cytology slide from a cytology specimen that was fixed in ethanol- or methanol-based fixatives.

Slides: 1 slide

Additional Information: Processed slides will be retained by Mayo Medical Laboratories and will not be returned to the client.

Specimen Minimum Volume

1 slide

Specimen Stability Information

Specimen Type Temperature Time
Slide Ambient (preferred)

Reject Due To









Reference Values

An interpretative report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; 8 a.m. - 5 p.m.

Analytic Time

5 days

Performing Laboratory

Mayo Medical Laboratories in Rochester

Test Classification

This test was developed and its performance characteristics determined by Mayo Clinic in a manner consistent with CLIA requirements. This test has not been cleared or approved by the U.S. Food and Drug Administration.

CPT Code Information


LOINC Code Information

Test ID Test Order Name Order LOINC Value
FALKC ALK on Cytology Specimens, FISH In Process


Result ID Test Result Name Result LOINC Value
55151 Result Summary 50397-9
55152 Result In Process
55153 Interpretation In Process
55154 Reason for Referral 42349-1
55155 Specimen 31208-2
55156 Source 31208-2
55159 Tissue ID No LOINC Needed
55157 Released By No LOINC Needed


If not ordering electronically, complete, print, and send an Oncology Test Request Form (T729) with the specimen (