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