Nucleofection of Parasite Forms: An Electroporation-Based Transfection Method to Deliver Fluorescent Protein Encoding-Plasmids Into Sporozoite Nucleus

To deliver plasmids into sporozoite nuclei by nucleofection, begin with a suspension of isolated, viable sporozoites - motile, infectious stage of parasites - in buffer. Sporozoites are slender-shaped cells enclosed by an outer plasma membrane and an underlying inner membrane complex consisting of a series of flattened vesicles and proteins critical for structural stability and motility.

Centrifuge the suspension to pelletize the sporozoites. Resuspend the sporozoite pellet in a suitable volume of nuclear transfection buffer, supplemented with fluorescent protein-encoding plasmids. Nuclear transfection buffer with high buffering capacity and ionic strength ensures efficient transfection while preserving sporozoite functionality.

Transfer the suspension to a nuclear transfection cuvette. Place the cuvette into the holder of a nucleofection device. Run the appropriate nucleofection program.

During nucleofection, specifically applied, short, high-voltage pulses, along with buffer constituents, temporarily disrupt the plasma membrane and inner membrane complex, forming transmembrane pores, which provide plasmids access into the cytoplasm.

Simultaneously, these high-strength electric fields also disturb the double-layered nuclear membrane surrounding the nucleus that develops transient gaps, facilitating direct entry of plasmids into the nucleus, without need for cell division.

Once nucleofection is complete, cellular and nuclear membrane pores reseal, restoring membrane integrity and homeostasis while trapping plasmids inside the nucleus.

Remove the cuvette from the device. Add suitable media for sporozoite recovery and transfer into a fresh tube. Successfully nucleofected sporozoites with plasmid DNA express fluorescent proteins.