Karyotyping is a commonly performed laboratory procedure that takes a detailed look at the chromosomes of a cell. It’s done to check for chromosomal abnormalities usually in individuals who have birth defects, infertility, or a family history of certain genetic diseases. It may also be used to check how a person may respond to certain medications or treatments.

Preparation for Karyotyping Test

Karyotyping is typically done as part of a routine test or when a chromosomal abnormality is suspected. It does not require any specific preparation prior to the test. However, it is important to tell the doctor or lab technician if you are pregnant or taking any medications that may affect results.


A technician usually takes blood or amniotic fluid samples, which will then be taken to the lab to be analyzed. The technician will then use certain chemicals or alcohol to prepare the sample for the evaluation. They will then put the sample on a slide and take pictures of the chromosomes using a microscope. The technician will then use special software to analyze the chromosomes and compare them to an average immediately.

Types of Karyotyping

There are two main types of karyotyping, conventional karyotyping and fluorescence in situ hybridization (FISH). Conventional karyotyping involves preparing a sample with special chemicals and taking pictures of the chromosomes under a microscope. FISH is slightly more complex and involves a fluorescent dye that highlights the chromosome material for easier analysis. This method offers greater precision in identifying chromosomal abnormalities.


The risks associated with karyotyping are quite minimal and are generally restricted to the procedure used to collect the sample. For instance, there is some risk associated with taking a blood sample if the patient has a fear of needles. Taking amniotic fluid requires the use of a thin needle, which carries its own set of risks.

Why Karyotyping is Important

Karyotyping is a vital tool in helping diagnose chromosomal disorders, such as Down Syndrome and Edwards Syndrome, as well as other genetic disorders. It can also be used to check how an individual may respond to a specific medication or treatment and to detect certain cancers, such as leukemia.

When to Get Karyotyping

Karyotyping is typically recommended when chromosomal abnormality is suspected, if a person has infertility issues, when there is a family history of a certain genetic disorder, or when a pregnant woman is found to have an abnormality on an ultrasound. It is also useful in diagnosing certain blood-related cancers.