Transfection is a common method used to introduce nucleic acids into cultured cells and is useful in assessing a variety of cellular functions. Especially for cancer research, transfection of molecules into cell lines can help understand the role of proto-oncogenes or tumor suppressor genes. Transient and stable transfection services are routinely offered by biology contract research (CRO) companies with cell lines they have in-house or with cell lines provided by the sponsor. Altogen labs offers both transient transfection services and stable transfection services (development of cell line stably expressing protein of interest).
CROs often produce and purify plasmid in milligram quantities suitable for both transient and stable transfection studies, which is more cost effective than plasmid preparation kits purchased from manufacturers. These offers not only cost savings, but time savings as well. Stable transfection requires not only more plasmid DNA material, but also expression construct to encode gene of interest, compatible promoter to drive gene expression, and at least one antibiotic resistance gene to enable selection of positive clones. Reporter genes (such as GFP, RFP, or YFP) are often also encoded in stable cell line expression vector to confirm expression and visualize cells expressing gene of interest. Cell biology studies are preformed using fluorescent gene expression as a marker to characterize cell phenotype of positive clones.
Biology CRO companies often have standard plasmids already available to validate DNA vaccine delivery and formulation strategies. Such studies usually include method optimization for the most efficient delivery and expression of the desired product.
RNAi studies often rely of siRNA transfection method, purity of siRNA material, and transfection efficiency into target cancer cell line (in vitro experiments) or target tissue (in vivo experiments). These experiments rely of extensive and time consuming optimization studies to optimize transfection experimental conditions. There are commercially available transfection kits that are pre-optimized for both in vitro and in vivo research applications.