CHROMOSOME ANALYSIS, AMNIOTIC FLUID
TURNAROUND TIME: 8 to 11 days
TESTING METHODOLOGY: Chromosome analysis of metaphase cells
- Collect: 20-30 mL amniotic fluid in sterile centifuge tubes or bottles; discard the first 2 mL collected to reduce risk of maternal cell contamination.
- Min. Collection: 7 mL amniotic fluid; low specimen volumes and grossly bloody specimens may require additional culturing resulting in longer turnaround times; volumes < 7 mL may result in lack of adequate cells for analysis.
- Transport: 20-30 mL amniotic fluid in sterile centrifuge tubes of bottles at 20-25oC
- Stability: Ambient: 24 hours; Refrigerated: 24 hours Frozen: unacceptable
- Unacceptable Conditions: Frozen or non-sterile specimens
Methods: Giemsa band (G-band) analysis at approximately a 550 band level; 2 karyotypes, analysis of 5 metaphase cells and count of 15 metaphase cells from separate colonies or 20 metaphase cells from monolayers
Test Variables: This study involves culturing of living cells. Therefore, turnaround times given represent average times which are subject to multiple variables.
Indications for Use:
- Increased risk of a chromosome abnormality in the fetus based on maternal serum prenatal screening tests
- Fetal abnormality detected on ultrasonography
- Advanced maternal age
- Previous offspring with a chromosome abnormality
- Family history of a chromosome abnormality