MDL Microsatellite Instability (MSI)
Department: Molecular Diagnostics
Test Synonym(s): LAB5660, MSI
CPT Codes: 81301
Methodology: Amplified by PCR using fluorescent primers specific for 5 mononucleotide loci; analyzed by capillary electrophoresis
Tube Type: Lavender top (EDTA) for control
Specimen: Control: blood or normal tissue paraffin embedded tissue: block, 5-10 unstained slides or 5 curls (NOTE: slides and curls 10 micron thick with accompanying before and after cut H&E slides)) AND Tumor tissue paraffin embedded tissue: block, 5-10 unstained slides or 5 curls (NOTE: slides and curls 10 micron thick with accompanying before and after cut H&E slides)
Pediatric Requirements: 2 microtainers blood
Volume: 1 tube (control)
Minimum Volume: 2 microtainers blood
Temperature: EDTA: room temperature or refrigerated, paraffin block: room temperature
Stability: EDTA: Room temperature: 2 days Refrigerated: 7 days
Reasons for Rejection: PET: de-calcified tissue (may or may not yield interpretable results and is dependent on the degree of fixation during processing). Client will be notified by Molecular Diagnostic Laboratory if specimen is rejected
Days Performed: Once a week - variable days
Times Performed: Batched
TAT: 10 days
Significance: Used for identification of Lynch Syndrome and therapy response (associated with Colorectal Cancer or Endometrial cancer)
Special Instructions: Call or email the Molecular Diagnostics Laboratory at 615-343-8121 or moleculardiagnosticlab@vumc.org if assistance is needed for specimen submission or if the patient has received a transfusion in the prior 2 weeks or has a history of a stem cell transplant.
Click here to print the Molecular Diagnostics requisition.
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