therein after that the mixture 307 of the competent cell suspension and aluminum beads was placed into an ice bath 311 for 30 minutes then the mixture 307 of the competent cell suspension and aluminum beads was placed under a temperate of 42 u00b0 c for 20 seconds to perform heat shock 313 after heat shock 313 was performed the mixture 307 of the competent cell suspension and aluminum beads was placed into an ice bath 311 for 2 minutes poured into 900 u03bcl of a soc medium and shaking cultured under a temperature of 37 u00b0 c for 45 minutes after being cultured the mixture 307 of the competent cell suspension and aluminum beads was spread on an lb agar plate 315 containing a specific antibiotic fig3 b shows that after being stored at a relatively higher temperature of u2212 20 u00b0 c for 6 months competent cells of the tg group and competent cells of the tg b group of the were not limited to being stored at temperatures of u2212 70 u00b0 c to u2212 80 u00b0 c for storing competent cells moreover transformation efficiency of the competent cell suspensions of the wt b group and the tg b group containing aluminum beads was raised 3 10 times respectively as compared with that of.