The HANABI-PVI Metaphase Spreader has been designed to provide optimized environmental conditions for metaphase chromosome spread preparations. Temperature, humidity and airflow are set and rapidly stabilized so when chromosomes are dropped and spread on microscope slides, they are dried in a consistent and reproducible manner. Excessive spreading and chromosome overlaps are minimized, giving rise to better yields of analysable metaphases. The chromosome spreading process for conventional G-banding (or equivalent) and FISH analysis of samples derived from blood cells or bone marrow samples, is now more streamlined and can easily be carried out regardless of skill level. Protocols requiring cells and chromosomes that are spread on the entire slide can be achieved using the tilted slide.