Since it is a new product, only few application notes are available at the moment. We are very interested in whether the K4® transfection system is useful for your application. We therefore provide a "full-size" kit or the amount you need for your applications free of charge (Offer for Cooperation), if you are willing to share your results with us.

Eukaryotic cells can detect foreign substances such as lipopolysaccharides, bacterial or viral nucleic acids and proteins by the innate immune system and take defensive measures against the infiltration of potential pathogenic or initiate apoptotic processes. In addition, the presence of any cell-damaging substances is communicated to the neighboring cells through messengers, accordingly establishing a defensive attitude, without having direct contact to the pathogen.

The knowledge that virtually all transfection methods are affected of the defenses of the innate immune system led to the development of the K4® Transfection System consisting of the K4® Transfection Reagent and the K4® Multiplier. The K4® Transfection Reagent is based on powerful cationic lipids, whereas the K4® Multiplier decreases the cells´ ability to detect foreign nucleic acids. Especially hard to transfect cells often express endosomal or cytosolic sensors that can detect nucleic acids. In contrast to the K2® Multiplier, the K4® Multiplier as its further development inhibits both groups of sensors.

In this way, in many cases significant increased transfection efficiencies combined with improved vitality of the cells can be achieved, in comparison to traditional lipofection reagents. The K4® Transfection System is therefore suitable for transient and stable transfection of mammalian cell lines and primary cells with DNA (plasmids, bacmide), RNA (mRNA, miRNA, and siRNA), and modified nucleic acids (e.g. antisense oligonucleotides). Areas of application are particularly the production of proteins, antibodies, and viruses (e.g. adenoviruses, AAV, lentiviruses), cotransfections of different nucleic acids, genome editing (e.g. CRISPR/Cas9, CRISPR/Cpf1) and gene silencing (gene knockdown).

The K4® Transfection System is part of a temporal development series of transfection reagents from Biontex, which includes in particular the following reagents: METAFECTENE® < METAFECTENE® PRO < K2® Transfection System < K4® Transfection System .With the development degree the probability of a successful transfection increases (see also General Selection Aid).