On‐Chip Acousto Thermal Shift Assay for Rapid and Sensitive Assessment of Protein Thermodynamic Stability

Abstract

Thermal shift assays (TSAs) have been extensively used to study thermodynamics of proteins and provide an efficient means to assess protein–ligand binding or protein–protein interactions. However, existing TSAs have limitations, such as being time consuming, labor intensive, or having low sensitivity. Herein, an acousto thermal shift assay (ATSA), the first ultrasound enabled TSA, is reported for real‐time analysis of protein thermodynamic stability. It capitalizes the coupling of unique acoustic mechanisms to achieve protein unfolding, concentration, and measurement on a single microfluidic chip within minutes. Compared to conventional TSA methods, the ATSA technique enables ultrafast (at least 30 times faster), highly sensitive (7–34 folds higher), and label‐free monitoring of protein–ligand interactions and protein stability. ATSA paves new avenues for protein analysis in biology, medicine, and fast diagnosis.

Emerging on-chip surface acoustic wave technology for small biomaterials manipulation and characterization

“…Most recently, Ding et al 19 achieved to measure the protein stability by pattering the protein molecules in the pressure nodes and/or antinodes (Fig. 1D).…”

Acoustically manipulating internal structure of disk-in-sphere endoskeletal droplets

“…For instance, optical and nanorobotic methods have been successfully used for manipulation in nano and micro scale 1 – 3 . Electrical and acoustic methods have achieved high throughput particle manipulation for applications such as bioparticle patterning, protein characterization, cell separation and droplet sorting, etc 4 – 6 . However, an advanced manipulation of the internal structure of complex colloids has been a long-standing challenge and rarely reported so far.…”

Three-dimensional heating and patterning dynamics of particles in microscale acoustic tweezers

“…For instance, mammalian cells can be seriously harmed, if the temperature exceeds 43 • C, and denaturation of lots of proteins generally occurs at temperatures above 45 • C. 46 On the other hand, acoustically induced heating can also be used for active temperature control of cell and protein suspensions. 47,48 An increase of temperature due to the acoustothermal effect has to be considered anyhow, what recently came into the focus of interest. [49][50][51] So far, experimental investigations of acoustically induced heating in acoustofluidic systems were carried out either by invasive techniques, like thermocouples or resistance thermometers, [52][53][54] or by noninvasive techniques, e.g.…”