How is karyotype studied?

The karyotype is determined by a blood test and allows to know the number and structure of chromosomes. The sample is placed in a special dish or tube and allowed to grow in the laboratory. 

Cells are then taken from the new sample and stained. The lab specialist uses a microscope to examine the size, shape, and number of chromosomes in the cell sample. The dyed sample is photographed to show the arrangement of the chromosomes, which is called karyotype.