[Sodium chloride step gradients centrifuge to fractionate foreign DNA fragment for microinjection].

DNA microinjection is the most popular and reliable method of producing transgenic animals. The purity of foreign DNA plays an important role for the success of microinjection. In this study, we introduced the use of sodium chloride step gradients in fractionating foreign DNA fragment for microinjection. The data demonstrated that,compared with the conventional agarose gel extraction method, NaCl purification scheme of toreign DNA could improve the treated embryo survival and foreign DNA intergration rate markedly.