Cell Lysis and Protein Extraction in a Microfluidic Device with Detection by a Fluorogenic Enzyme Assay

A critical requirement for achieving a micro total analytical system for the analysis of cells and their constituent proteins is to integrate the lysis and fractionation steps on-chip. Here, an experimental microfluidic system integrating the lysis of bacterial cells and the extraction of a large intracellular enzyme, β-galactosidase, is demonstrated. The β-galactosidase is detected and quantified using a fluorogenic enzyme assay and a numerical model. While the focus is on the lysis of typical Gram-negative bacterial cells (E. coli), the techniques described here could, in principle, be applied to a variety of different cell types.