Duplicate cultures are initiated for each blood sample/ other sample types received for chromosome analysis (karyotype). Blood lymphocytes are cultured in complete media supplemented with the mitogen, phytohemeagglutinin (PHA) to divide and cultured for 72 hours routinely.
Figure 1: Chromosomes are stained and photographed for study and depicts 23 pairs or 46 chromosomes (each pair contributing 1 chromosome from father and 1 from mother) including pair of sex chromosomes with male showing one X chromosome and one Y chromosome (Normal Male Karyotype: 46, XY.
Figure 2: Abnormal Karyotype of child showing Trisomy of chromosomes #21 (Downs Syndrome) due to extra copy of chromosome 21. (Abnormal Female Karyotype: 47, XX, +21).