How is a karyotype produced?

Karyotypes are prepared from mitotic cells that have been arrested in the metaphase or prometaphase portion of the cell cycle, when chromosomes assume their most condensed conformations. A variety of tissue types can be used as a source of these cells.

What are the three steps taken to create a karyotype?


  1. Sample collection and tissue culture.
  2. Arresting cells at metaphase.
  3. Swelling, separating and spreading chromosomes using hypotonic solution.
  4. Separating chromosomes onto the slide.
  5. Staining or banding.
  6. Arranging the results- a karyotype.

How do you karyotype a human chromosome?

To observe a karyotype, cells are collected from a blood or tissue sample and stimulated to begin dividing; the chromosomes are arrested in metaphase, preserved in a fixative and applied to a slide where they are stained with a dye to visualize the distinct banding patterns of each chromosome pair.

What is the karyotype?

A karyotype is an individual’s collection of chromosomes. The term also refers to a laboratory technique that produces an image of an individual’s chromosomes. The karyotype is used to look for abnormal numbers or structures of chromosomes.

What are the 5 steps to making a chromosome spread?

Terms in this set (6)

  1. Add cell sample to the culture media, a sterile solution that helps the cells grow.
  2. Culture, or grow the cells in a lab, for up to two weeks.
  3. Arrest, or halt, cells in metaphase. …
  4. Swell and drop cells onto microscope slides. …
  5. Stain with Giemsa dye and observe the chromosomes under a microscope.
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How do you tell if a karyotype is male or female?

Females have two X chromosomes, while males have one X and one Y chromosome. A picture of all 46 chromosomes in their pairs is called a karyotype. A normal female karyotype is written 46, XX, and a normal male karyotype is written 46, XY.

Can a karyotype determine gender?

A karyotype is simply a picture of a person’s chromosomes. … The 23rd pair of chromosomes are the sex chromosomes. They determine an individual’s sex. Females have two X chromosomes, and males have an X and a Y chromosome.

Why are karyotypes useful?

Why the Test Is Useful

Karyotyping can be used to detect a variety of genetic disorders. For example, a woman who has premature ovarian failure may have a chromosomal defect that karyotyping can pinpoint. The test is also useful for identifying the Philadelphia chromosome.

Why are karyotypes useful diagrams?

karyotypes allow you to study differences in chromosome shape, structure, and size. … By looking at kayotypes you should be able to determine the number of autosomes and sex chromosomes present.

How is a chromosome spread obtained?

DNA:DNA in situ hybridization is usually carried out on chromosome spread preparations where chromosome and nuclei are released from cells and spread on a glass microscope slide. … Ideally, cells and nuclei should be spread to a single layer and there should be little or no contact between cells and nuclei.

What is metaphase spread?

Analysis of chromosomes arrested during metaphase. The chromosomes are highly condensed at this stage of cell division and are visible under a light microscope. ( From the journal Nature-Glossary). ( NCI Thesaurus)

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Why chemical fixative is important in the preparation of karyotype?

NOTE: The fixed cells can be stored in fixative solution for months at 4°C. Besides protecting cells in their swollen state, the fixative solution removes lipids and denatures proteins. These events make the cell membrane fragile and, as a result, make the chromosome spreading easily.