Karyotyping

Karyotyping is a representation of chromosomes captured at metaphase. When the chromosomes reach the metaphase phase, the division is halted and then the chromosomes are arranged by size into a karyotype. There are several different kinds of banding including, G-banding, Q-banding, C-banding, and R-banding. G-banding dyes heterochromatin in the chromosomes, Q-banding finds areas rich in A-T vs. G-T and dyes them to identify the homologous chromosomes. C-banding dyes centromeric heterochromatin and R-banding is the reverse of G-banding . Today, softwares can analyze the banding types once it is dyed and arrange them. Moreover, DNA in the nucleus are found in two forms, heterochromatin and euchromatin. Heterochromatin is tightly packed DNA material, whereas euchromatin is loosely packed chromosomes that become active during transcription.