A micrometer-sized affinity bead (red) is (i) taken up into a cell by phagocytosis, (ii) photochemically released from phagosomes, (iii) optically trapped by the cell, and (iv) isolated by cell lysis for subsequent analysis of captured intracellular analyte (green). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.