Ordering Recommendation

Recommended reflex test to differentiate between Lynch syndrome-associated and sporadic colorectal cancer in tumors showing loss of MLH1. This test is not recommended for non-colorectal cancers including endometrial cancers showing loss of MLH1; instead, consider MLH1 Promoter Methylation (3004308). 

New York DOH Approval Status

Testing is not New York state approved. Specimens from New York clients will be sent out to a New York state-approved laboratory.

Specimen Required

Patient Preparation

Tumor tissue

Specimen Preparation

Tumor Tissue: Formalin fix (10 percent neutral buffered formalin, not decalcified) and paraffin embedded tissue with at least 25 percent tumor burden. Protect from excessive heat. Tissue block will be returned after testing. Transport tissue block or 8 unstained 5 micron slides. (Min: 5 slides).
Transport block and/or slide(s) in a tissue transport kit (ARUP Supply # 47808) available online through eSupply using ARUP Connect or contact ARUP Client Services at 800-522-2787.

New York State Clients: Transport tissue (Formalin-fixed, paraffin embedded) or 10 unstained, nonbaked slides and 1 slide stained with hematoxylin and eosin.

Storage/Transport Temperature

Room temperature. Also acceptable: Refrigerated. Ship in cooled container during summer months.

Unacceptable Conditions

Less than 25 percent tumor. Specimens fixed in any fixative other than 10 percent neutral buffered formalin. Decalcified specimens (except in EDTA). Decalcified specimens in EDTA will require a client approved disclaimer.


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 (e.g., "Choose best block"), or individual orders for each sample submitted. A Pathologist Block Selection Fee (ARUP test code 3002076) 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.

Our pathologists will review every case to determine if there is an adequate tumor area for testing. Submitted specimens should contain >25 percent tumor. Specimens may be canceled, and a new block requested if there is not an acceptable area for extraction or if block/tissue has been decalcified (except in EDTA).

Samples that produce less than the optimal concentration of DNA input and/or samples decalcified in EDTA will require a disclaimer for testing or be canceled.


Ambient: Indefinitely; Refrigerated: Indefinitely; Frozen: Unacceptable


Massively Parallel Sequencing




10-15 days
If reflexed, add 5-12 days.

Reference Interval

Interpretive Data

Compliance Category

Laboratory Developed Test (LDT)


BRAF (NM_004333) exon 15 is evaluated to detect hotspot mutations. If BRAF V600E mutation is not detected, then MLH1 Promoter Methylation will be added. Additional charges apply. See Additional Technical Information for more information.

Hotline History


CPT Codes

81210; If reflexed, add 81288


Component Test Code* Component Chart Name LOINC
2002148 Block ID 57723-9
3017450 BRAF REFL Int 58415-1
* 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 click the sidebar link to access the Interface Map.


  • Colon cancer
  • Colorectal cancer
  • Lynch Syndrome
  • MLH1
  • Rectal cancer
  • V600E
BRAF Mutation Detection with Reflex to MLH1 Promoter Methylation