what's the difference between tissue/cell electroporation and electroporation -mediated transformation?

Question

i am studying biotechnology and i get confused of those two kinds of gene transfer. the first one belongs to direct transfer, the second one belongs to indirect (mediated) gene transfer. but what the difference?

Answer 1

Direct = Transfection
Transfection is the term used to describe the introduction of foreign material into eukaryotic cells. This typically involves opening transient pores or 'holes' in the cell plasma membrane, to allow uptake of material. Whilst this is most commonly genetic material such as supercoiled plasmid DNA,siRNA, the term can also be applied to antibodies or other proteins. Transfection is frequently carried out by mixing a cationic lipid with the material to produce liposomes, which, after application, fuse with the cell plasma membrane and deposit their cargo inside. Whilst the term transfection is most often used for mammalian cells, transformation is generally used for the same process as applied to bacteria, and occasionally plants.

Indirect = Electroporation
Electroporation, or electropermeabilization, is a significant increase in the electrical conductivity and permeability of the cell plasma membrane caused by an externally applied electrical field. It is usually used in molecular biology as a way of introducing some substance into a cell, such as loading it with a molecular probe, a drug that can change the cell's function, or a piece of coding DNA.

Pores are formed when the voltage across a plasma membrane exceeds its dielectric strength. If the strength of the applied electrical field and/or duration of exposure to it are properly chosen, the pores formed by the electrical pulse reseal after a short period of time, during which extracellular compounds have a chance to enter into the cell. However, excessive exposure of live cells to electrical fields can cause apoptosis and/or necrosis - the processes that result in cell death.

In molecular biology, the process of electroporation is often used for the transformation of bacteria, yeast, and plant protoplasts. In addition to the lipid membranes, bacteria also have cell walls which are different from the lipid membranes and are made of peptidoglycan and its derivatives. However, the walls are naturally porous and only act as stiff shells that protect bacteria from severe environmental impacts. If bacteria and plasmids are mixed together, the plasmids can be transferred into the cell after electroporation. Several hundred volts across a distance of several millimeters are typically used in this process. Afterwards, the cells have to be handled carefully until they have had a chance to divide producing new cells that contain reproduced plasmids. This process is approximately ten times as effective as chemical transformation.