Pay careful attention to centrifugation speeds prior to Nucleofection™; be sure not to centrifuge the cells at higher than 90xg. Any trypsinization should use the minimal amount of reagent and time necessary in order to minimize stress to the cells, since the Nucleofection™ will stress the cells as well. Neutralizing the trypsin with serum-containing media or trypsin inhibitor is imperative. Post Nucleofection™, (make sure the media is prewarmed) add the recommended amount of medium to the cuvette and gently transfer the cells with the provided pipettes without pipetting up and down (the key is to be as gentle as possible, especially at this step). The only exception to this is on the 96-well Shuttle™ where a gentle pipetting up and down is necessary due to the small volume. For other tips and suggestions, please contact our Scientific Support Team.