What Does a Cytogeneticist Do?

Cytogenetics is also a branch of genetics that conducts genetic research at the cellular level, including behavior and transmission mechanisms and their biological effects.

Cytogenetics

Cytogenetics is also a branch of genetics that conducts genetic research at the cellular level, including behavior and transmission mechanisms and their biological effects.

The combination of genetics and cytology established cytogenetics, mainly from a cytological perspective, especially from

Early research on cytogenetics

The branch disciplines derived from cytogenetics are mainly

Chromosomes carry genetic material. Understanding the structure and function of chromosomes is one of the important tasks of genetics. Abnormal numbers and structures of chromosomes are associated with many diseases, including hereditary diseases related to obstetrics and gynecology. Therefore, chromosome analysis under the microscope is a useful tool for examining and diagnosing genetic disorders in obstetrics and gynecology.

1. Guidelines for cytogenetic analysis:

affirm and exclude certain known chromosome syndromes;

Sexual differentiation and abnormal development;

infertility;

Repeated abortions or stillbirths;

Pregnancy serum screening or fetal ultrasound examination shows a pregnancy at risk of aneuploidy;

Genetics of gynecological tumors.

2. Source of specimens for cytogenetic examination:

The staining system is prepared from dividing cells. These cells can be taken directly from fresh tissue, such as villous tissue, or from cell culture, such as the culture of amniotic fluid cells. The most widely used specimen for karyotyping is peripheral blood, from which chromosomes of T lymphocytes are prepared for analysis.

3. Chromosome banding:

Air-dried chromosome drops must be suitable for staining before being placed under a microscope for karyotype analysis.

Chromosome staining Use dyes with affinity to DNA such as Giemsa to make chromosomes dark. This staining method can be used to examine the fragile parts of chromosomes, chromosome break syndrome, and chromosome damage caused by radiation. G band This is the conventional method for analyzing human chromosomal diseases. One disadvantage of the R band G band is that the telomere area is lightly stained. The R band can be used to obtain the staining band pattern that is exactly opposite to the G band. Q band and DNPI band The Q band is stained with quinacin nitrogen mustard. The chromosome shows a fluorescent band pattern with different light and dark under ultraviolet light. Q bands can be used to identify satellite regions with centromeric chromosomes. The C band and the counterstain band are not commonly used. nucleoli tissue area (NOR) silver staining, etc.

4. Flow karyotype analysis:

For cell suspension samples, flow cytometry can be used for flow karyotype analysis. Flow karyotyping measures the DNA content of individual chromosomes. The chromosome suspension was fluorescently stained, and then a photon amplifier was used to measure the fluorescence intensity of each chromosome excited by laser. This test can be used for gender identification, aneuploidy detection, and determination of abnormal chromosome size.

5. In situ hybridization technology:

Probes for in situ hybridization can be labeled with nuclide or fluorescein. In recent years, the use of fluorescence in situ hybridization has become common. With multicolor fluorescent labeling, multiple probes can be used at once to check multiple specific DNA sequences. If multicolor fluorescence in situ hybridization is combined, the resolution and accuracy of chromosome analysis can be enhanced with the assistance of a digital fluorescence microscope and an imaging processing system. ^[1]