Electrocompetent bacteria are prepared by growing cultures tomid-log phase, washing the bacteria extensively at low temperature,and then resuspending them in a solution of low ionic strengthcontaining glycerol. DNA is introduced during exposure of thebacteria to a short high-voltage electrical discharge.
In Vitro Translated Xenopus Mos Kinase Assay Protocol. In response to progesterone, immature Xenopus oocytes mature to eggs that can be fertilized. The Mos protein kinase is essential for oocyte maturation, most likely due to its ability to activate the MAP kinase cascade. This MAP kinase cascade eventually leads to the activation of Cdc2/cyclin B and entry into M phase. In this protocol, tagged Mos kinase is translated in vitro, immunopurified, and used in a kinase assay.