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Rh Genotyping - C/c Antigen, Fetal

Test Codes

Blood Center of Wisconsin: BCW3850. Order as a Miscellaneous Send Out.

Department

Send Outs

Specimen Collection Criteria

Collect: Fetal specimen as well as maternal and paternal specimens, as described below:

• Fetal: 7-15 mL amniotic fluid, cultured amniotic cells (2.0x10⁶ cells minimum), or Chorionic Villus specimen (CVS).
• Maternal/Paternal: Two Lavender-top EDTA tubes from each the mother and the father.

Send both maternal and paternal whole blood with the fetal sample to ensure that the antigen in question can be detected in this assay. The maternal sample is also used to rule out maternal contamination in the fetal sample. Include serologic typing results for both parents on the test requisition.

Physician Office/Draw Specimen Preparation

• Maintain fetal specimens at room temperature (20-26°C or 68-78.8°F) prior to transport.
• Do not centrifuge maternal and paternal specimens. Maintain whole blood at room temperature (20-26°C or 68-78.8°F) prior to transport. 

Preparation for Courier Transport

Transport: Fetal specimen [15 mL amniotic fluid (Minimum: 7.0 mL), cultured amniotic cells (Minimum: 2.0x10⁶ cells), or chorionic villus sample] and maternal and paternal specimens [10 mL whole blood (Minimum: 2.0 mL) from both the mother and the father], at room temperature (20-25°C or 68-77°F).

Rejection Criteria

Specimens not collected and processed as indicated. 

In-Lab Processing

• Maintain fetal specimens at room temperature (20-26°C or 68-78.8°F) prior to transport.
• Do not centrifuge maternal and paternal specimens. Maintain whole blood at room temperature (20-26°C or 68-78.8°F) prior to transport.

Transport: Fetal specimen [15 mL amniotic fluid (Minimum: 7.0 mL), cultured amniotic cells (Minimum: 2.0x10⁶ cells), or chorionic villus sample] and maternal and paternal specimens [10 mL whole blood (Minimum: 2.0 mL) from both the mother and the father], at room temperature (20-25°C or 68-77°F).

Storage

Specimen Stability for Testing:

Room Temperature (20-26°C or 68-78.8°F): 7 days
Refrigerated (2-8°C or 36-46°F): 14 days
Frozen (-20°C/-4°F or below): Unacceptable

Specimen Storage in Department Prior to Disposal:

Specimen retention time is determined by the policy of the reference laboratory. Contact the Send Outs Laboratory with any questions.

Laboratory

Sent to Versiti, Milwaukee, WI.

Performed

Monday – Friday.
Results available in 5-7 days.

Reference Range

By report.

Test Methodology

Allele-Specific Polymerase Chain Reaction (PCR).

CPT Codes

81479, 86905x2.

Contacts

Last Updated

11/6/2023