Analysis of deoxyribonuclease activity by conjugation-free fluorescence polarisation in sub-nanolitre droplets

Abstract

Deoxyribonuclease (DNase) assay using ethidium bromide (EtBr) molecules by conjugation-free fluorescence polarisation under visible light in a droplet-based microfluidic chip.

Analysis of Phosphatase Activity in a Droplet-Based Microfluidic Chip

“…The enzyme inhibition assay is essential in high-throughput drug screening since several samples must be screened. Droplet-based microfluidic system can be used as a platform to perform enzyme inhibition assays due to their advantages of rapid mixing of reagents and low reagent/sample consumption [ 24 , 25 ]. Here, dPIA was demonstrated through a simple dose–response assay using ethyl-3,4-dephostatin as the phosphatase inhibitor ( Figure 4 a).…”

“…The microfluidic device was designed and prepared based on our previous reports [ 24 , 25 ]. A simple T-junction PDMS microfluidic device featuring an oil inlet, a sample inlet, and an outlet was fabricated using standard soft lithography techniques.…”

“…Lab-on-a-chip technologies have been successfully demonstrated in the fields of pharmacology, cell biology, and biochemistry [ 21 ]. Using droplet-based microfluidic system, we have previously reported protein–protein interactions analysis [ 22 ], SNP detection [ 23 ], RNase activity assay [ 24 ], and DNase activity assay [ 25 ]. Therefore, to identify phosphatases and screen for phosphatase inhibitors, droplet-based microfluidics has the potential to be a low-cost, high-throughput screening technology.…”

Reagentless protein-based electrochemical biosensors

“…For years the detection of clinically relevant proteins and other biomarkers has been attained in point-of-care settings mostly using fluorescence anisotropy (also often called fluorescence polarization). [1][2][3][4][5] In fluorescence polarization, the occurrence of a specific protein-protein complex is measured through binding-induced variations in the tumbling of a surfaceattached fluorophore. 6 Such a technique is one of the most suitable methodologies for quantifying the levels of specific proteins in clinically relevant samples, as it does not necessitate washing steps to eliminate unbound reagents.…”