transferred to sporulation media to form a tetrad containing four haploid spores. Tetrads can then be prepared with Zymolyase, or another enzyme, to digest the wall of the ascus. The spores are then separated with a micromanipulator needle and deposited in separate positions on a petri dish. Tools Traditionally, tetrad dissection has a reputation as "black art". However, instruments have since been developed specifically for tetrad dissection; the most advanced allow easy and semi-automated separation of tetrads. Most micromanipulators use a glass fiber needle to which the spores adhere due to the formation of a water meniscus between the agar and the needle. See also Synthetic genetic array Saccharomyces cerevisiae Ascus Homologous recombination Genetic recombination Ascospore References External links "Crosses, diploids, and tetrads" Fungus genetics Plant genetics