High Transformation Efficiency of Escherichia coli with Plasmids by Adding Amino Modified Silica-nanoparticles

The calcium chloride method is an efficient and convenient technique to prepare Escherichia coli competent cells. The transformation efficiency of the competent cells when prepared in the laboratory is generally below 106 cfu μg-1 (colony forming units μg-1) DNA and thus its application is limited in some extent. Here we report the utilization of a-SiNPs (amino modified Silica-Nanoparticles) as a help material to improve the transformation efficiency of E. coli competent cells that are prepared with calcium chloride method. Addition of a-SiNPs increases the transformation efficiency of E. coli to 107-108 from below 106 cfu μg-1 DNA in the laboratory.