Featured Article
Monday March 01, 2004
Introducing foreign genes into cells wasn’t a novel idea created by scientists. The phenomenon had been going on for centuries in prokaryotes, such as E. coli, which pass genes amongst each other to share certain genetic traits. Taking the tip from nature, researchers all over use transfection—the insertion of genes into cells—as a routine procedure for a wide variety of experiments. Developed over the last few decades, transfection can now be done using several strategies and protocols.
Since the early 1970s, academia and industry have come up with several methods to bring double-stranded and single-stranded RNA and DNA into most types of both dividing and non-dividing cells. What defines the different methods is the vector—the vehicle that carries the genes into the cell. Unlike the frustration-inducing and inefficient protocols of the early days, newer vectors are designed to make the transfection easier, faster, more reliable and less toxic. Vectors made of different combinations of innovative lipids, polymers and/or other proprietary compounds are popular. The technology is based on the fact that lipid micelles are negative and do well in carrying negatively charged genetic material and binding to the negatively charged plasma membrane. Some companies tether the lipids to ligands that will bind to specific receptors on the target cell.
Also popular are retroviruses, adenoviruses, lentiviruses and adeno-associated viruses. The type of virus you choose depends on how long you want the inserted gene to be expressed. If your goal is for the gene to be inserted into the host genome, use retroviruses to transfect dividing cells. For quiescent cells, use lentiviruses and adeno-associated viruses. Use adenoviruses for transient expression of the transfected gene.
Many of the vectors are packaged into convenient kits. Some specialize in transfecting DNA, while others are specific for siRNA, which is used for RNA-mediated interference. Kits for high-throughput and large-batch transfections are also available.
Take a look below at the various products on the market. Though some experts insist that finding the perfect vector or experimental conditions takes a lot of trial and error, you can maximize your efforts with the detailed specifications on the package.