To separate liposomes from unencapsulated lucigenin, size-exclusion chromatography is used. This can be done with pre-packed commercial columns (for instance with 8.3 mL Sephadex G-25 Medium, also referred to as 'PD-10 desalting columns'), which are time-efficient, or with manually packed columns (for instance by hydrating 2.2 g Sephadex G-50 Fine for a few hours with the eluent and then pouring the suspension into a thin glass column with cotton wool or a sintered glass frit and slowly draining the excess eluent). Sephadex columns should be run using gravity alone, without applying any pressure.