Mechanical Protein Unfolding and Translocation by AAA+ Proteases

Abstract

molecular analysis with sensitivity and selectivity. Here we describe an innovative biophysical solution to prevent hemolysis in blood plasma separation devices for precision molecular diagnostics. In order to avoid biochemical interferences, RBCs are exposed to both fluidic drag force and gravitational force after the computation of transition fluid velocity from vertical up-flow to sedimentation was in the range of 1.3 to 2.5 mm/sec in the design of microfluidic separation device. A membrane filter for filtration was positioned on top of a vertical up-flow channel to reduce clogging of RBCs by gravity-assisted cells sedimentation. As a result, separated plasma volume was increased about 4-fold (2.4 mL plasma after 20 min with 38 % hematocrit human whole blood) and hemoglobin concentration in separated plasma was decreased about 90 % due to the prevention of RBCs hemolysis in comparison to a filter-in-bottom configuration. On-chip plasma contains~90 % of protein and~100 % of nucleic acids compared to off-chip centrifuged plasma, showing comparable target molecules recovery. This simple and reliable blood plasma separation platform can be easily integrated with downstream detection module for sample-toanswer POC diagnostics.