Release of intracellular proteins by electroporation with preserved cell viability.

Extraction of intracellular proteins from cells is often an important first step for conducting molecular biology and proteomics studies. Although ultrasensitive detection and analytical technology at the single molecule level is becoming routine, protein extraction techniques have not followed suit and still call for complete lysis that leads to cell death. In principle, with refined extraction techniques, intracellular proteins can potentially be extracted without killing the cell. In this Letter, we demonstrate that electroporation is capable of releasing intracellular proteins from adherent Chinese hamster ovary cells while preserving the cell viability. By tuning the duration and intensity of an electric pulse, we were able to control the average amount of protein release and the percentage of viable cells after the operation. Our results indicate that a substantial fraction of the cell population was able to release proteins under electroporation and survive the procedure. Interestingly, at the single cell level, the probability for cell death does not increase with more protein release. This work paves the way to extracting and analyzing intracellular proteins while keeping cells live.