Microsatellite Instability by PCR (MSI)
HNPCC Screen, MSI Testing, SOFT LAB: MMSIG, SOFT GENE: MMSI
Specimen Collection Criteria
Collect: Formalin-fixed, paraffin-embedded tumor block and separate normal tissue block with corresponding H&E slides. Tissue should be well fixed and well processed. Average tissue size 5.0 mm2.
- DNA will be assessed for quality. If it is deemed unacceptable, testing will be cancelled with client notification.
- The specimen must be accompanied by a completed requisition and must contain the patient name, date of birth, collection date, ordering physician, and source of specimen.
Physician Office/Drawsite Specimen Preparation
Maintain paraffin-embedded tissue at room temperature (20-26°C or 68-78.8°F) until transport.
Preparation for Courier Transport
Transport: Paraffin-embedded tissue, at room temperature (20-26°C or 68-78.8°F).
- Decalcified tissue.
- Fixatives other than 10% neutral buffered formalin.
- Improper labeling or inadequate information.
Specimen Stability for Testing:
Room Temperature (20-26°C or 68-78.8°F): Indefinitely
Refrigerated (2-8°C or 36-46°F): Unacceptable
Frozen (-20°C/-4°F or below): Unacceptable
Specimen Storage in Department Prior to Disposal:
Room Temperature (20-26°C or 68-78.8°F): 7 days
Royal Oak Clinical Molecular Pathology Laboratory.
Results available in 7 days.
Microsatellite instability: 0-9 markers. Microsatellite stable, unstable-low, unstable-high. Results obtained with tumor DNA are compared with results obtained with the patients normal DNA.
DNA is extracted from the tissue. Primers to six NCI consensus microsatellites are used to amplify both tumor and normal DNA. Fluorescently labeled products are analyzed by capillary electrophoresis. Three additional microsatellite primer sets are used if necessary for clarification of results.
Microsatellite stable, unstable-low, unstable-high.
Detects instability of microsatellite loci associated with a loss or suppression of DNA mismatch repair complex.
Epiphenomenon or heritable colorectal adenocarcinoma MSI conditions.
SOFT LAB: MMSIG, SOFT GENE: MMSI
Microtainer® and Vacutainer® are registered trademarks of Becton, Dickinson and Company.
UroVysion® is a registered trademark of Abbott Laboratories. ThinPrep® is a registered trademark of Hologic, Incorporated.
This directory currently reflects information only for specimens collected and/or processed at the Farmington Hills,
Grosse Pointe, Royal Oak, and Troy campuses.