Abstract: A flow cell comprises a top structure including a first set of luer fittings, channels coupled to the first set of luer fittings, where the channels include flow-through cylindrical electrodes, electrical connectors connected to the electrodes to connect to at least one external circuit, and a second set of luer fitting to attach to the channels and to external fluid connectors, and a bottom structure including a set of luer fitting receptacles to connect to the first set of luer fittings, optical windows to transmit in light from a light source and to transmit out scattered light from a sample for detection and analysis, and indexing surfaces to index on an external electrophoretic mobility measurement instrument.