Microfluidic affinity selection of active SARS-CoV-2 virus particles

Abstract

We report a microfluidic assay to select active severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viral particles (VPs), which were defined as intact particles with an accessible angiotensin-converting enzyme 2 receptor binding domain (RBD) on the spike (S) protein, from clinical samples. Affinity selection of SARS-CoV-2 particles was carried out using injection molded microfluidic chips, which allow for high-scale production to accommodate large-scale screening. The microfluidic contained a surface-bound aptamer directed against the virus’s S protein RBD to affinity select SARS-CoV-2 VPs. Following selection (~94% recovery), the VPs were released from the chip’s surface using a blue light light-emitting diode (89% efficiency). Selected SARS-CoV-2 VP enumeration was carried out using reverse transcription quantitative polymerase chain reaction. The VP selection assay successfully identified healthy donors (clinical specificity = 100%) and 19 of 20 patients with coronavirus disease 2019 (COVID-19) (95% sensitivity). In 15 patients with COVID-19, the presence of active SARS-CoV-2 VPs was found. The chip can be reprogrammed for any VP or exosomes by simply changing the affinity agent.

High Sensitivity Extended Nano-Coulter Counter for Detection of Viral Particles and Extracellular Vesicles

“…This resulted from the high specificity afforded by the selection chip and its affinity agent. 35 As seen from the data shown in Figure 4C,D, we successfully identified all COVID-19(+) samples using our affinity selection chip and the XnCC. TEM images of the captured and released SARS-CoV-2 virions can be seen in Figure 4E.…”

“…As seen in Figure A,B, the COVID-19(−) saliva samples generated no discernible signals in the XnCC RPS data traces. This resulted from the high specificity afforded by the selection chip and its affinity agent . As seen from the data shown in Figure C,D, we successfully identified all COVID-19­(+) samples using our affinity selection chip and the XnCC.…”

Aptamer‐based strategies against SARS‐CoV‐2 viruses

“…In another study using CoV2-RBD-1C as the recognition and capture element, aptamers were attached to the UV/O 3 -activated cyclic olefin polymer surface of a plastic chip via photocleavable linker. Scope et al constructed a viral particle (VP) selection chip and used it for SARS-CoV-2 VP detection [70] (Figure 6e). The VP chip achieved efficient capture (about 94% recovery) with release efficiency of 89%.…”

“…Reproduced with permission. [70] Copyright 2022, the American Association for the Advancement of Science.…”

“…(e) A VP selection chip for SARS‐CoV‐2 VP detection. Reproduced with permission [70] . Copyright 2022, the American Association for the Advancement of Science.…”