Karyotype of NIH, C57BL/6 and Razi strains of laboratory mice (Mus musculus)

The laboratory mouse is recog nized as the pre-emin ent model for genetic research. awareness of chromosomal patterns of experimental animals increases their value for a variety of different fields of study. we aimed to study mitotic chromosome preparations from nih, c57bl/6 and razi strains of mice, which are outbred, inbred and partially inbred laboratory mice respectively. bone marrow cells were prepared from 36 male and female mice, 12 from each strain, and stained by use of giemsa staining and g-banding methods. karyotypin g ofthe samples showed that there was no difference in chromosomal numb ers amon g the three mice strains, also the metaph ase preparati ons of their diploid cells contained 40 chromos omes (2n = 40) and all chromosomes we re telocentric. however, some differences in band tonality and the size of chromosomes were seen.