DMSO enhanced one-pot HDA-CRISPR/Cas12a biosensor for ultrasensitive detection of Monkeypox virus.

Abstract

We present a dimethyl sulfoxide (DMSO)-enhanced one-pot HDA-CRISPR/Cas12a biosensor for the ultrasensitive detection of the monkeypox virus (MPXV). The MPXV B6R gene was initially amplified using DMSO-enhanced helicase-dependent amplification (HDA) in the bottom of the reaction tubes. DMSO was employed to enhance the amplification efficiency of HDA. CRISPR/Cas12a reagents, pre-added to the caps of the reaction tubes, were subsequently combined with HDA products to generate fluorescence signals. This DMSO-enhanced HDA-CRISPR/Cas12a biosensor enables the detection of synthetic B6R DNA within 1 hour, with a detection limit of 9 aM and a dynamic range of 10 aM to 100 pM. Our work demonstrated that 5% DMSO can enhance the sensitivity of the HDA -CRISPR/Cas12a assay by four orders of magnitude. For clinical applications, this approach can detect as low as 0.4 copies/μL of MPXV pseudovirus. A DMSO-enhanced HDA-CRISPR/Cas12a lateral flow biosensor (LFB) was developed for MPXV point-of-care testing (POCT), achieving a LOD of 10 fM. This method exhibits high specificity in distinguishing the monkeypox virus from closely related orthopoxviruses, including variola, vaccinia, cowpox, ectromelia, and camelpox. The assay is rapid (sample-to-answer times less than 1 h), cost-effective, and compatible with both fluorescence detection and the LFB for visual readouts.