Inactivated/Replace Test
Effective Date
10/20/2025
Included in Report
Replacement Test
MLH1 – “MLH1 Promoter Methylation” replaced by MLH1P – “MLH1 Promoter Methylation”
Back to Test UpdatesInactivated/Replace Test
Inactivated Test Details
Mnemonic
MLH1
Ordering Code
3624180
CPT-4 Codes(s)
81288
Replacement Test Details
Mnemonic
MLH1P
Ordering Code
3600543
CPT-4 Codes(s)
81288
Turnaround Time
9 - 14 days
Performed
Varies
Legacy Code
MLH1P
Example Report
Specimen Information
Collect
Tumor tissue
Specimen Preparation
Send formalin fixed paraffin embedded tissue block or 5 unstained 5
micron slides in a tissue transport kit. Include surgical pathology report.
If multiple specimens (blocks or slides) are sent to ARUP, they must be accompanied by one of
the following: an order comment indicating that the ARUP pathologist should choose the
specimen most appropriate for testing, or individual orders for each sample submitted. A
Pathologist Block Selection Fee will be added to orders that utilize the first option. If multiple
specimens are sent to ARUP without a request for pathologist block/slide selection or individual
orders, they will be held until clarification is provided.
micron slides in a tissue transport kit. Include surgical pathology report.
If multiple specimens (blocks or slides) are sent to ARUP, they must be accompanied by one of
the following: an order comment indicating that the ARUP pathologist should choose the
specimen most appropriate for testing, or individual orders for each sample submitted. A
Pathologist Block Selection Fee will be added to orders that utilize the first option. If multiple
specimens are sent to ARUP without a request for pathologist block/slide selection or individual
orders, they will be held until clarification is provided.
Minimum Volume
5 slides (if using)
Transport Temperature
Room temperature
Rejection Criteria
Fixative other than 10 percent neutral buffered formalin, bone specimens submitted in non-EDTA decalifier, less than 25 percent tumor.
Stability
Room temperature: Indefinite
Refrigerated: Indefinite
Frozen: Unacceptable
Refrigerated: Indefinite
Frozen: Unacceptable
Methodology
Real-Time Polymerase Chain Reaction/Fluorescence Resonance Energy Transfer
Reference Range
See report
Performing Laboratory
ARUP Reference Laboratory
New York DOH Approval Status
Yes