A method is proposed for providing at least one defined volume of a targetconstituent (164) of asample (134). The method comprises the following steps:- providing at least one metering capillary (110) having at least twoopenings (112, 114)；- at least partly filling the metering capillary (110) with the sample(134)；- carrying out a constituent separation for the at least partialseparation of at least twoconstituents (150, 154) of the sample (134) inside the metering capillary(110)； and- dividing the metering capillary (110) into at least two partialpieces (160, 162), whereinat least one of the partial pieces (160) contains the defined volume of thetargetconstituent (164).
