PMS2, also known as PMS1 protein homologue 2, is a DNA mismatch repair (MMR) protein. The PMS2 protein forms a heterodimer with the MLH1 protein which is then activated in the presence of ATP; this complex coordinates the binding of other proteins that repair DNA errors arising during cell preparation for cell division.
The loss of PMS2 expression in tumors can be helpful in identifying hMLH1 mutation carriers. PMS2 gene defects account for a small but significant proportion of colorectal cancers and for a substantial proportion of tumors with microsatellite instability.
PMS2
- Immunohistochemistry (IHC)
Specimen Requirements
Preferred specimen (FFPE block):
A formalin-fixed, paraffin-embedded (FFPE) tissue block is the preferred specimen type. Use 10% NBF fixative; do not use zinc or mercury fixatives.
If submitting slides (instead of a block):
Submit the following. All slides cut at 4–5 microns. Please use positively-charged slides and 10% NBF fixative.
H&E slide: One (1) unbaked, unstained slide for H&E staining (required)
Cut Slides: Two (2) positively charged unstained slides for each IHC test/antibody ordered
Specimen identification:
Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
A formalin-fixed, paraffin-embedded (FFPE) tissue block is the preferred specimen type. Use 10% NBF fixative; do not use zinc or mercury fixatives.
If submitting slides (instead of a block):
Submit the following. All slides cut at 4–5 microns. Please use positively-charged slides and 10% NBF fixative.
H&E slide: One (1) unbaked, unstained slide for H&E staining (required)
Cut Slides: Two (2) positively charged unstained slides for each IHC test/antibody ordered
Specimen identification:
Block and slide identifiers should be clearly written and match exactly with the specimen ID and specimen labeling as noted on the requisition.
Storage and Transportation
Slides may be stored at room temperature; transport with cold pack, making sure cold pack is not in direct contact with specimen.
NYS Clients: Please provide Date and Time of Collection.
CPT Code(s)*
88342 x 1 or 88341 x 1 (qualitative IHC) or 88360 (quantitative/semi-quantitative, manual) or 88361 x 1 (quantitative/semi-quantitative, computer assisted)
Turnaround time
1-2 Days
Image Analysis for Global: 2 Days
Image Analysis for (Tech-Only): 2 Days
Tech-Only (stain only): 24 Hours
Level of Service
- Global
- Tech Only
Integrations
Request electronic integrations →
New York Approved: Yes
*The CPT codes provided with our test descriptions are based on AMA guidelines and are for informational purposes only. Correct CPT coding is the sole responsibility of the billing party. Please direct any questions regarding coding to the payor being billed.
Biomarkers
Immunohistochemistry (IHC)
| Expression | |||||
|---|---|---|---|---|---|
| PMS2 | |||||
Last Updated: March 19, 2026