Both diluents, EDB and EDP, are phosphate buffers containing 2-Methyl-2H-isothiazol-3-one and 5-bromo-5-nitro-1,3-dioxane as preservatives. The difference lies in the fact that EDP also contains EDTA. This particular component is essential in preventing the formation of fibrin clots when diluting plasma samples, which result in clogging of the VirClia Lotus system. Thus, when working with plasma samples, EDP must be used, while with serum samples, EDB and EDP are valid.

When using plasma samples, in addition, a new special method is necessary. In them, a predilution of the sample with EDP is carried out. This step is included in all plasma methods.