Surface area to volume ratio
Journal of Experimental Microbiology and Immunology (JEMI)
Vol. 14: 98-100
Copyright © April 2010, M&I UBC
The Effects of the Ratio of
Surface Area to Volume on
Transformation Efficiency in
Escherichia coli
K-12
Eliana Pouchard, Steve Teng, and Cameron Wong
Department of Microbiology & Immunology, UBC
In the process of transformation, bact eria take up DNA fr om the environment through their cell wall. To induce competence in the cells, the DNA for uptake must first attach to the cell surface prio r to passing throug h the membrane. Previous studies on the effect of surface area on transformation e fficiency have shown d ecreased transformation efficiencies in large
E.coli
cells as compared to smaller strains. The reasons remain unknown. We proposed that the surface ar ea to volume ratio (SA:V) to be the determining parameter on transformation effici ency, with a higher ratio leading to higher transformation efficiencies. In order to asse ss this model, we transformed wild type
Escherichia coli
(BW25113) and a smaller mutant strain (JW2500) with different amounts of the plasmid vector pUC19.The mutant strain JW2500 with a lower SA:V ratio but a similar surface area to the parent strain displayed 70% ± 5% of the number of transformants from the w ild-type strain BW25113. Suc h results suggest a direct relationship between SA:V ratio and the observ ed changes in transf ormation efficiency.
Transformation is the introduction of DNA into prokaryotic cells and the genetic alteration of a cell resulting from the uptake, genomic incorporation, and expression of foreign genetic material (3).The ability to transform Escherichia coli with plasmid DNA is crucial for a vast number of molecular biology procedures (2,
5). Cells which undergo transformation must first become competent, which can be achieved through several methods, such as calcium chloride treatment or
electroporation
Vol. 14: 98-100
Copyright © April 2010, M&I UBC
The Effects of the Ratio of
Surface Area to Volume on
Transformation Efficiency in
Escherichia coli
K-12
Eliana Pouchard, Steve Teng, and Cameron Wong
Department of Microbiology & Immunology, UBC
In the process of transformation, bact eria take up DNA fr om the environment through their cell wall. To induce competence in the cells, the DNA for uptake must first attach to the cell surface prio r to passing throug h the membrane. Previous studies on the effect of surface area on transformation e fficiency have shown d ecreased transformation efficiencies in large
E.coli
cells as compared to smaller strains. The reasons remain unknown. We proposed that the surface ar ea to volume ratio (SA:V) to be the determining parameter on transformation effici ency, with a higher ratio leading to higher transformation efficiencies. In order to asse ss this model, we transformed wild type
Escherichia coli
(BW25113) and a smaller mutant strain (JW2500) with different amounts of the plasmid vector pUC19.The mutant strain JW2500 with a lower SA:V ratio but a similar surface area to the parent strain displayed 70% ± 5% of the number of transformants from the w ild-type strain BW25113. Suc h results suggest a direct relationship between SA:V ratio and the observ ed changes in transf ormation efficiency.
Transformation is the introduction of DNA into prokaryotic cells and the genetic alteration of a cell resulting from the uptake, genomic incorporation, and expression of foreign genetic material (3).The ability to transform Escherichia coli with plasmid DNA is crucial for a vast number of molecular biology procedures (2,
5). Cells which undergo transformation must first become competent, which can be achieved through several methods, such as calcium chloride treatment or
electroporation