20 mL (15 mL min.) Amniotic fluid in a sterile screw-capped container. Sample to be collected under strict aseptic precautions. Ship refrigerated immediately. DO NOT FREEZE. Specimen must reach within 48 hours. Test is recommended between 15-20 weeks of gestation. Duly filled Form G, Chromosome & FISH Analysis Requisition form & Consent form for Prenatal genetic testing is mandatory. Samples shall be accepted only from registered genetics clinics under PCPNDT Act. It is recommended to discard the initial 2-3 mL of aspirate, since this first draw may contain some maternal cells trapped within the needle during insertion.