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Prenatal G-band Karyotype


Amniotic fluid
Test performed by: LabPLUS - Dept. Diagnostic Genetics - Cytogenetics


Specimen Collection
EDTA4 mL Adult EDTA Blood (Always Required)

Accompanying Maternal blood is required


Sterile Container20 mL Prenatal Sterile Container Amniotic Fluid
Sterile Container20 mg Prenatal Sterile Container Chorionic Villus
Turnaround Time: Between 2 weeks and 3 weeks
Assay Method

Chorionic villus and Amniotic fluid is grown in culture and cells are arrested at metaphase to produce visible G-banded chromosomes for analysis.
The number of cells analysed and counted are based on the NPAAC guidelines.
Limitations: micro-deletions/duplications (below 5-8MB) and cryptic translocations may not be excluded.


Diagnostic Use and Interpretation

A G-banded karyotype gives us the ability to visualise chromosomes and assess their number and structure. Prenatal karyotyping is performed when certain chromosome changes are detected by rapid aneuploidy screening (QFPCR of FISH) or microarray. Prenatal karyotyping can also be requested for familial chromosome rearrangements. FISH can be used on metaphase chromosomes to identify cryptic chromosome rearrangements.

Diagnostic Genetics Prenatal Analysis


Contact Information

To contact the Cytogenetics team:

Auckland City Hospital   (09) 307 4949
Lablink   ext 22000
Diagnostic Genetics General Enquiries   ext 22008
Cytogenetics Office   ext 22012


Specimen Transport Instructions for Referring Laboratories

Specimens to be kept at room temperature (>8 degrees Celsius to <24 degrees Celsius) and sent to LabPlus urgently. Samples must arrive in the laboratory on the day of the procedure or the following day.



Last updated at 14:55:35 23/06/2025