Karyotype Protocol
A karyotype is a graphic showing all the chromosomes of a cell. Karyotype analysis is useful for detecting, or ruling out, certain genetic disorders. The protocol to create a karyotype starts with live cells, such as white blood cells; the chromosomes are isolated, stained and photographed to create the karyotype.
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Sample
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The starting sample for a karyotype must include live cells that have nuclei and that can reproduce. Red blood cells will not work because they lack a nucleus, but white blood cells are often used in a karyotype protocol.
Culture
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The chromosomes must be obtained from an actively dividing cell, so the technician cultures the cells to induce them to grow and divide.
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Slides
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The technician stops cell division with a fixative, then places the cells onto microscope slides. The stain the technician uses depends on how much detail is needed in the final image.
Photography
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Some cells will be in a stage of cell division that shows all the chromosomes (metaphase). The technician takes a photograph of one of these cells.
Final Image
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The technician identifies the chromosomes in the photograph, cuts out their images, and arranges them in numerical order, with the sex chromosomes (X and Y) appearing last.
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References
Resources
- Photo Credit syringe loading image by kryptajuliett from Fotolia.com
