Male chromosomes. Coloured light micrograph of a normal, full complement of male chromosomes, taken during the metaphase stage of mitosis (cell division) in order to compile a karyotype, a document of all 46 chromosomes arranged in homologous pairs. Here the chromosomes are unpaired; pairing might be done by cutting up the image & pairing off each chromosome according to length, shape and banding pattern. The banding is due to trypsin/leishman treatment. The 23rd pair contains the sex chromosome and is denoted XY in males and XX in females. Magnification: x2400 at 6x7cm size.