The meaning of the term
transfection has evolved. The original meaning of transfection was "infection by transformation",
i.e. introduction of DNA (or RNA) from a prokaryote-infecting virus or
bacteriophage into cells, resulting in an infection. Because the term transformation had another sense in animal cell biology (a genetic change allowing long-term propagation in culture, or acquisition of properties typical of cancer cells), the term transfection acquired, for animal cells, its present meaning of a change in cell properties caused by introduction of
DNA (or other nucleic acid species such as
RNA or
SiRNA). Because of this strict definition of
transfection, optical transfection also refers only to the introduction of nucleic acid species. The introduction of other impermeable compounds into a cell, such as organic
fluorophores or semiconductor
quantum nanodots is not strictly speaking "transfection," and is therefore referred to as "optical injection" or one of the many other terms now outlined. The lack of a unified name for this technology makes reviewing the literature on the subject very difficult. Optical injection has been described using over a dozen different names or phrases (see bulleted lists below). Some trends in the literature are clear. The first term of the technique is invariably a derivation of word laser, optical, or photo, and the second term is usually in reference to injection, transfection, poration, perforation or puncture. Like many cellular perturbations, when a single cell or group of cells is treated with a laser, three things can happen: the cell dies (overdose), the cell membrane is permeabilised, substances enter, and the cell recovers (therapeutic dose), or nothing happens (underdose). There have been suggestions in the literature to reserve the term
optoinjection for when a therapeutic dose is delivered upon a single cell, and the term
optoporation for when a laser generated shockwave treats a cluster of many (10s to 100s) cells. as those using the term to denote the simultaneous dosing of clusters of many cells or the optical tweezing or isolation of intracellular material.
Terms under deliberation •
Optoporation: Has been suggested to mean the dosing of a cluster of cells with a shockwave mediated mechanism, which usually results in a doughnut shaped therapeutic zone. Some of the above was reproduced with permission from. ==Methods==