It is enough to cook salmon once, but it must be cooked. After boiling, quickly insert it into the ice to make it more flexible.

Yeast two-hybrid, salmon sperm dna is to protect the dna you want to transform, because foreign genes will be recognized and degraded after being transferred into eukaryotes. Adding a certain amount of salmon sperm dna will make your yeast transform your dna by degrading salmon sperm dna.