Determination of DNA entrapment into liposomes using short monolithic columns.

A high-performance liquid chromatography (HPLC) method for the determination of DNA entrapment efficiency in liposomes has been developed. Plasmid DNA was encapsulated into positively charged liposomes. Non-entrapped DNA was separated by ultracentrifugation from liposomes and supernatant was chromatographed on Convective Interaction Media (CIM) DEAE disk. The elution of DNA was monitored by the absorbance at 260 nm and the quantity of DNA in the tested sample was calculated from the integrated peak areas using the appropriate standard curve. This method is fast, simple, precise and does not require any kind of DNA labelling in contrast with mostly used methods for determination of DNA entrapment efficiency.