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Test Code IL28V Interleukin 28B (IL28B) Variant (rs12979860)

Specimen Required

Multiple genotype tests can be performed on a single specimen after a single extraction. See Multiple Genotype Test List in Special Instructions for a list of tests that can be ordered together.


Submit only 1 of the following specimens:


Specimen Type: Whole blood

Container/Tube: Lavender top (EDTA)

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send specimen in original tube.

Specimen Stability Information: Ambient (preferred)/Refrigerated


Specimen Type: Saliva

Patient Preparation: Patient should not eat, drink smoke, or chew gum 30 minutes prior to collection.

Supplies: DNA Saliva Collection Kit (T786)

Container/Tube: Saliva Swab Collection Kit (T786: fees apply)

Specimen Volume: One swab

Collection Instructions: Collect and send specimen per kit instructions.

Specimen Stability Information: Ambient


Specimen Type: DNA

Container/Tube: 2 mL screw top tube

Specimen Volume: 100 mcL (microliters)

Collection Instructions:

1. The preferred volume is 100 mcL at a concentration of 250 ng/mcL.

2. Include concentration and volume on tube.

Specimen Stability Information: Frozen (preferred)/Ambient/Refrigerated


1. New York Clients-Informed consent is required. Please document on the request form or electronic order that a copy is on file. An Informed Consent for Genetic Testing (T576) is available in Special Instructions.

2. If not ordering electronically, complete, print, and send a Pharmacogenomics Test Request Form (T797) with the specimen (

Useful For

Predicting responsiveness of genotype 1 hepatitis C viral infections to combined pegylated-interferon and ribavirin-based therapies in whole blood specimens

Method Name

Real-Time Polymerase Chain Reaction (PCR) With Allelic Discrimination Analysis

Reporting Name

IL28B Genotype

Specimen Type


Specimen Minimum Volume

Blood: 0.4 mL
Saliva: 1 swab

Specimen Stability Information

Specimen Type Temperature Time
Varies Varies

Reject Due To









Reference Values

An interpretive report will be provided.

Day(s) and Time(s) Performed

Monday through Friday; 9 a.m.

Analytic Time

3 days (not reported on Saturday or Sunday)

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

81283-IL28B (interleukin 28B [interferon, lambda 3]) (eg, drug response), rs12979860 variant

LOINC Code Information

Test ID Test Order Name Order LOINC Value
IL28V IL28B Genotype 60297-7


Result ID Test Result Name Result LOINC Value
BA0128 IL28B Genotype 60279-7
BA0129 IL28B Phenotype 53040-2
BA0130 Interpretation 69047-9
BA0131 Additional Information 48767-8
BA0201 Method 49549-9
BA0202 Disclaimer 62364-5
BA0132 Reviewed by In Process