The present invention provides a method of analyzing a sample containing an analyte to be qualitatively and/or quantitatively determined, comprising a binding step and a washing step, wherein the binding step comprises: interacting the analyte with beads having a density m1; obtaining a structure of packed beads comprising quantifiable bead complexes having a density m2; and the washing step comprises: dispersing the packed beads in a liquid medium having a density d>m2 and m1; and separating the liquid medium and the beads comprising the quantifiable bead complexes.