Fish genomic DNA preparation

Useful as a quick easy method for large amounts of good quality DNA from fish blood. Can be scaled down but as fish red cells are nucleated be sure to to get a sufficiently small amount of blood for a miniprep.

Notes - Do not use more than 300µl of blood in this protocol. Scale up if required. 300µl of fish blood should yield at least 0.5mg of DNA. Contamination can be a problem in Southern blot experiments where large amounts of plasmids are being routinely used as very small amounts carried over from, for example, a contaminated tip can overwhelm a Southern blot. Therefore all reagents should be made up from scratch, autoclaved and marked GENOMIC DNA ONLY and only fresh tips should be used. The same points should be noted when restriction digesting and running the DNA ie ideally seperate enzymes and buffers should be kept for this purpose.