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Alpha-Fetoprotein (AFP-AF), Amniotic Fluid

Methodology

Hypertech Immunoassay
AFP is the primary screen for open-neural tube defects, anencephaly, and spina bifida cystica.

Performing Laboratory

Western Pennsylvania Hospital

Specimen Requirements

20 mL to 30 mL of amniotic fluid collected as follows:
1. Withdraw fluid into a sterile, plastic syringe. The type of plastic syringe used is extremely important and should be approved for tissue culture work. Toxic substances leech out of some plastics and inhibit cells from growing in culture. This laboratory recommends the use of Becton-Dickinson Plastipak® syringes.
2. Discard first 3 mL of fluid to help prevent contamination with maternal cells.
3. Change syringes and withdraw an additional 20 mL to 30 mL of fluid which should yield enough viable cells for successful analysis.
4. Fluid may remain in plastic syringe if it is capped tightly or it may be transferred to a screw-capped, sterile, plastic tube.
5. Fluid should be sent to laboratory immediately. Do not chill, overheat, or irradiate amniotic fluid as this will decrease viability of cells.
Note:  1. The following information is required for processing:
A. First day of last menstrual period
B. Date ultrasound performed
C. Gestational age by ultrasound
D. Collection date

2. Gestational age must be between 14 to 26 weeks.
3. A patient information form must accompany the specimen.

Reference Values

An interpretive report will be provided.

All abnormal results are called back and discussed with the ordering physician.

Day(s) Test Set Up

Monday through Friday