Karyotyping is done in which phase of cell cycle-

A karyotype is a photographic representation of a stained metaphase spread in which the chromosomes are arranged in order of decreasing length.A variety of techniques for staining chromosomes have been developed. With the widely used Giemsa stain (G banding) technique, each chromosome set can be seen to possess a distinctive pattern of alternating light and dark bands of variable widths . The use of banding techniques allows identification of each chromosome, and can detect and localize structural abnormalities (Robbins Basic Pathology, 9 th edition. page : 263)