Table of Karyotypes and Spreads (normal humans)

male female
Chromosome spread with 
chromosomes shown by 
bright field G-banding 
Karyotype shown by 
bright field G-banding 
of chromosomes
Idiogram of 
G-banded chromosome		 Same as for male 
(but without the Y)
Chromosome spread 
with chromosomes shown 
by fluorescent R-banding
Chromosome spread 
with chromosomes shown 
by fluorescent Q-banding 
Chromosome spread with 
C-banding that shows the 
centromeric region of each 
chromosome 		 Not available at this time
During most of the cell cycle, interphase, the chromosomes are somewhat less condensed and are not visible as individual objects under the light microscope. However during cell division, mitosis, the chromosomes become highly condensed and are then visible as dark distinct bodies within the nuclei of cells. The chromosomes are most easily seen and identified at the metaphase stage of cell division and most of the chromosome images in this gallery are pictures of metaphase chromomosomes.

 The number of chromosomes in human cells is 46 with 22 autosomal pairs (one of each type contributed by the mother and one of each type from the father) and 2 sex chromosomes - 2 X chromosomes for females (one from father and one from mother) or an X and a Y chromosome for males (the X from the mother and the Y from the father). The characteristic banding of chromosomes you will see in pictures here is obtained by staining with various dyes. The banding of chromosomes by using dyes was discovered in the late 1960's and before that cytogeneticists depended on chromosome length and position of a constriction to identify the individual chromosomes. The band width and the order of bands is characteristic of a particular chromosome - a trained cytogeneticist can identify each chromosome (1,2,3...22, X and Y) by observing its banding pattern under the microscope.

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Cytogenetics Gallery from UW Pathology Department
This gallery was developed by Cecilia Wendin, Doug Chapman, David Adler, and Kris Carroll. 1996