Enhancement and optimization of plasmid expression in femtosecond optical transfection

Cell transfection using femtosecond lasers is gaining importance for its proven ability to achieve selective transfection in a sterile and relatively non-invasive manner. However, the net efficiency of this technique is limited due to a number of factors that ultimately makes it difficult to be used as a viable and widely used technique. We report here a method to achieve significant enhancement in the efficiency of femtosecond optical transfection. The transfection procedure is modified by incorporating a suitable synthetic peptide containing nuclear localization and DNA binding sequences, assisting DNA import into the nucleus. We achieved a 3-fold enhancement in the transfection efficiency for adherent Chinese Hamster Ovary (CHO-K1) cells with this modified protocol. Further, in the presence of this biochemical reagent, we were able to reduce the required plasmid concentration by ~70% without compromising the transfection efficiency. Also, we report for the first time the successful photo-transfection of recently trypsinised cells with significantly high transfection efficiency when transfected with modified plasmid. This paves the way for the development of high throughput microfluidic optical transfection devices.