It has been widely demonstrated that the quality of samples preparations for chromosome analysis depends largely on the environmental conditions in which the final evaporation of the methyl acetate or ethyl acetate fixative takes place. The combined effects of temperature and relative humidity have a noticeable effect on the quality of the metaphase. Given that temperature and humidity are in constant variation, not only from season to season, but also throughout each day as a consequence of changes in the climatic conditions, it is easy to understand the requirement for a system that enables cytogenetists to work always under standardised conditions. OptiChrome has been specifically designed to minimize all problems related to those critical parameters, temperature and humidity, which are very unstable: it allows the technician to set and control both temperature and humidity, thus defining the ideal working conditions related to a certain protocol. When used along with the EuroClone reagents for Cytogenetics, OptiChrome will ensure excellent results, perfectly reproducible in any situation, as a final result a great improvement in efficiency and standardization can be easily achieved.