The problems of current transfection reagents:
- Low transfection efficiency or narrow spectrum: most transfection reagents work well on only a few common used cell types
- High toxicity: this is one of the major reasons that caused low efficiency in some sensitive cells.
Why do these problems exist? Many factors affect transfection efficiency, such as:
The ability of the reagent to compact the nucleic acids into the right sizes
- The correct amount of positive charges on the surfaces of the compacted complexes (Zeta Potential)
- The efficiency of the complexes in binding the cell surfaces
- The efficiency for the complexes to move into the cytoplasm
- The ability of the transfection reagent to protect the nucleic acids against the enzymes in the lysosomes and in the cytoplasm
- The efficient release of nucleic acids from endosomes
- Efficient transport into nucleus (for plasmid DNA)
Transfection is a complicated process. Although scientists understand quite a bit of the transfection and gene expression processes as well as many signal pathways, there are many other aspects that remain unknown.
Cells are not created equal. The following are some of the cell specific factors which may affect transfection:
- Cell proliferation status and health condition
- Receptors on the cell membrane
- lipid types and % of each type of lipids
- Glycosaminoglycans (GAG) types and content on the cell membrane
- Differences in endocytotic ability
- Other unknown properties that cause the responses of cells to transfection reagents vary significantly: some types of cells, such as suspension culture cells, primary cells, or stem cells are especially difficult to transfect with general-purpose tranfection reagents.
Even with the right transfection reagent, the protocol used on a specific type of cells needs to be optimized in order to achieve a high level of transfection efficiency and a low level of toxicity
Conclusion: It is impossible to create a universal transfection reagent that is able to work well on all cell types.
Cell type/cell line specific Avalanche® transfection reagents - a series of transfection reagents that were designed and optimized specifically with ingredients, formulations, and protocols for each type of cell lines or primary cells, in order to ensure the highest levels of efficiency while keeping the toxicity levels minimal.