Quantification of solid cell material by detection of membrane-associated proteins and peptidoglycan

Quantification of solid cell material (cell debris) is necessary for the optimisation of the efficiency of bioseparations. Cell debris can be quantified by detection of a component present in the cell wall that can act as a marker for cell debris. Membrane-associated proteins have previously been used as a marker for cell debris. This marker was quantified by SDS–PAGE with densiometry. In this paper cell debris quantification methods are presented that are faster and more accurate, i.e. membrane-associated protein quantification with the Protein 50 Labchip ® of Agilent Technologies, or that make use of peptidoglycan as marker for cell debris, i.e. a spectrophotometric muramic acid assay.