Test Details - Maternal Cell Rule-Out - Knight Diagnostic Laboratories

Background:

The presence of maternal cell contamination (MCC) in amniotic fluid or chorionic villus samples poses a serious preanalytical risk for prenatal misdiagnosis. This test is used to rule out the presence of maternal cell contamination within a fetal specimen.

Methodology:

Polymerase chain reaction: (PCR)-based comparison of multiple microsatellite markers in maternal vs. fetal samples.

Specimen Requirements:

Both maternal and fetal specimens required:

• Blood - Maternal:
  • 6 mL - EDTA (purple-top) or ACD (yellow-top) tube
  • If sending DNA: 100ng at a minimum of 100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)

OR

• Saliva - Maternal:
  • Saliva Kits (OGR2 ORAgene -500) used according to manufacturer instructions. Please contact KDL Client Services for a Saliva Collection Kit for patients that cannot provide a blood sample
  • If sending DNA: 100ng at a minimum of 100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)

• Amniotic Fluid - Fetal:
  • 10 mL direct amniotic fluid, OR
  • 2 T-25 flasks of cultured amniocytes (fully confluent)
  • If sending DNA: 100ng at a minimum of 100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)

OR

• Chorionic Villus - Fetal:
  • 10 -20 mg direct chorionic villus (CVS), OR
  • 2 T-25 flasks of cultured CVS cells (fully confluent)
  • If sending DNA: 100ng at a minimum of 100ng/µL (DNA must be extracted in a CLIA-certified laboratory or a laboratory meeting equivalent requirements as determined by the CAP and/or CMS)

A REQUISITION FORM MUST ACCOMPANY ALL SAMPLES. Please include detailed clinical information, including ethnicity, clinical history, and family history.

Test Performed (Days):

Weekly

Turn Around Time:

7-10 Days

Shipment Sensitivity Requirements:

• Package and ship specimen to remain cold, but not frozen.
• Ship via overnight express, using the FedEx priority overnight label provided.
• Contact Client Services for shipping kits and instructions at (855) 535-1522.

References:

1. Schrijver, I. et al. Testing for Maternal Cell Contamination in Prenatal Samples. J Mol Diagn. 2007 July; 9(3): 394–400.

Additional Info:

The lower level of sensitivity of the assay is approximately 5% maternal material in the fetal specimen.