System and method for separating an aqueous liquid into at least two cavities

A method for reducing leakage when separating an aqueous liquid comprising biological material into at least two cavities, the method comprising the steps of:

• a) providing a device having at least one void providing a separating space, and at least two cavities in fluidic connection with the void and separated by the separating space;
• b) supplying each of the at least two cavities with the aqueous liquid;
• and
• c) supplying the separating space with a separation liquid for separating the aqueous liquid into the at least two cavities such that leakage between said cavities is reduced;
• and,
• d) analyzing the aqueous liquid wherein the step of analyzing the aqueous liquid comprises determining the absence, presence, activity or concentration of biological material in the aqueous liquid,
• wherein the separation liquid in step c) comprises a polysiloxane having at least one hydroxy-group, and the %-mass ratio of hydroxy in the separation liquid is between 0.1% and 5%.