LION and repRNA are combined at a nitrogen:phosphate molar ratio of 15, where the nitrogens are present in the DOTAP component of LION and phosphates are present in the ribonucleotide components of the repRNA. The molar mass of DOTAP is ~663 g/mol and that of ribonucleotides is ~330g/mol.
Dilute repRNA in RNAse-free water to the desired concentration/dose
Using the molar masses specified above and the final concentration/dose of repRNA, dilute LION in a sucrose and sodium citrate buffer, using RNAse-free water, such that the final concentration of sucrose is 10% w/v and sodium citrate is 10mM.
Add the diluted RNA to the diluted LION formulation and pipette gently to mix. Keep on ice before use.