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Short Description : Cytogenetics Information Page

Key information links:

Chromosome Analysis-Blood(Constitutional)

Chromosome Analysis-Bone Marrow

Chromosome Analysis-Prenatal

Chromosome Analysis-Products of Conception

Chromosome Analysis-Solid Tumours

Fanconi Anaemia Testing


Molecular Cytogenetics (FISH)

Molecular Karyotype Analysis (microarray)

Sub-Telomere screening

For other DNA studies see:

Diagnostic Genetics Information Page

Molecular Genetics

Molecular Haematology

Download: - Diagnostic Genetics Brochure.pdf

Download: Form - DiagnosticGeneticsRequestForm.pdf

General Information:

The Cytogenetics Department at LabPlus diagnoses a wide variety of chromosomal abnormalities. There are four major areas of testing that are carried out:

1. Prenatal Diagnosis is performed on amniotic fluid, chorionic villus, foetal blood specimens and products of conception.

2. Postnatal constitutional cytogenetics is performed on blood and skin specimens, for cases of:

3. Cancer cytogenetics is performed on bone marrow and tumour specimens, with referrals for:

4. Molecular Cytogenetics or Fluorescent In situ Hybridisation (FISH) is performed on all types of tissue as required including histological specimens embedded in paraffin. Referrals are commonly either: Constitutional (Postnatal) Cytogenetics or Cancer (Acquired) Cytogenetics.

Chromosome preparations are made from dividing cells, which are at or near the metaphase stage of the mitotic cycle. The techniques used in the Cytogenetic laboratory all aim to produce a maximum number of cells undergoing mitosis. Samples are typically grown in culture media for a number of days or weeks. When a cell culture is ready to be harvested its growth is arrested by the addition of colcemid. Colcemid halts the cell cycle at metaphase where the nuclear DNA is organised into discrete chromosomes. Metaphase chromosomes are fixed onto microscope slides and are analysed by our cytogeneticists. The analysis is called a karyotype and it describes the chromosomal makeup (constitutional or acquired) of the individual from whom the tissue originated.

The cytogenetic department of LabPlus is an IANZ accredited laboratory and the Human Genetics Society Australasia (HGSA) Guidelines for standards in Cytogenetic Laboratories are incorporated into all procedures and quality assurance programs.

HGSA and National Pathology Accreditation advisory Council (NPAAC) recommended turnaround times are as follows:

  1. Lymphocyte cultures 18 days (non urgent).
  2. Bone marrow and tumour cultures 18 days.
  3. Amniotic fluid cultures 15 days.
  4. Chorion biopsies 15 days.
  5. Solid tissue cultures 28 days.

NB: The decision to repeat a prenatal specimen should be made in not more than 10 days.

Generally the laboratory meets or exceeds these guidelines. If for any reason these turn around times can not be achieved we will do our best to inform you. Non urgent cases are prioritised in consultation with the relevant clinician.

Last updated at 07:27:04 01/09/2014