siRNA Encapsulation into Exosomes Using Electroporation: An Electric Pulse Based Technique to Load siRNA into Exosomes

1. siRNA Encapsulation into Exosomes by Electroporation

1. Pre-chill the electroporation cuvette (see Table of Materials) on ice for 30 min before electroporation.
2. Mix 7.0 µg of exosomes (32 µL from 7 x 10¹² p/mL stock in PBS) with 0.33 µg of siRNA (12 µL from 2 µM stock in RNase-free water) in the microcentrifuge tube. Make up the volume to 150 µL with citric acid buffer (see Table of Materials). The exosome to siRNA molar ratio is 1:60 in this case.
3. Transfer the mixture to electroporation cuvette. Cap the cuvette and place it in the cuvette holder of the electroporator (see Table of Materials). Rotate the turning wheel 180° clockwise.
   NOTE: The wheel must be turned completely to the locked position, in order for the cuvette to contact the electrodes.
4. Select the desired electroporation program (e.g., X-01, X-05, A-20, T-20, T-30, etc.) and start electroporation by pressing the start button.
   NOTE: A successful pulse is indicated by showing "OK" on the display.
5. Once electroporated, remove the cuvette after turning back the wheel 180° counterclockwise. Withdraw the sample from the cuvette with the plastic pipette for further processing.