Poloxamer-gated one-step CRISPR test detects monkeypox virus in 40 minutes

Researchers have built a single-tube diagnostic platform that combines recombinase polymerase amplification with CRISPR/Cas12a detection while sidestepping the conflicts that normally force such assays into two separate steps. The system, called ChronoGate, uses a thermosensitive poloxamer to hold the detection machinery apart from the amplification reaction in both time and space, and it was applied to detect the monkeypox virus (MPXV) using the viral F3L gene as the target.

The problem the platform addresses is well known in the field of point-of-care testing. Real-time quantitative PCR remains the gold standard for pathogen detection, but it depends on professional laboratory conditions and is poorly suited to on-site use. CRISPR/Cas12a technology offers high specificity, yet its sensitivity on its own is limited, so it requires preamplification, typically by recombinase polymerase amplification (RPA). The conventional two-step RPA-CRISPR workflow, in which amplification and detection are carried out sequentially in separate handling stages, is prone to aerosol contamination. One-step systems such as SHERLOCKv2 avoid that handling but suffer from template competition, which reduces sensitivity by a reported 10- to 100-fold.

ChronoGate’s solution is a temporal-spatial separation strategy built on the phase behaviour of poloxamer. At temperatures below 25 °C, the poloxamer encapsulates the Cas12a protein together with its guide CRISPR RNA (crRNA), keeping the detection components physically separated from the amplification mixture. When the reaction is heated to 37 °C, the poloxamer releases the Cas12a/crRNA complex with a delay of approximately 8 minutes, allowing RPA amplification to proceed first and detection to begin afterwards within the same closed tube. This ordered “amplification-first, detection-later” sequence preserves the sensitivity of a two-step workflow while eliminating the tube-opening steps that create aerosol contamination risk.

The researchers determined the optimal reaction conditions to be 15% (w/v) poloxamer in a 15 μL reaction volume. Alongside the chemistry, the team developed a companion portable fluorescence detector to read out the Cas12a signal, making the whole system usable outside a standard laboratory.

Performance was assessed using the monkeypox virus F3L gene as the detection target. The platform achieved an encapsulation efficiency of 85.7%, meaning most of the Cas12a/crRNA complex was successfully sequestered by the poloxamer during the low-temperature setup phase. Sensitivity testing with serial dilutions of plasmid DNA showed a detection limit of 1 copy/μL, which the authors report as comparable to the conventional two-step method. That result is significant because it indicates the one-step format did not pay the usual sensitivity penalty associated with template competition in mixed one-pot reactions.

Specificity was evaluated by testing nontarget pathogens alongside the MPXV target. No cross-reactivity was observed, which the researchers cite as confirmation of good specificity for the assay.

The platform was then applied to clinical samples. Among 14 clinical specimens tested, the ChronoGate results showed 100% concordance with qPCR, the reference method. Total detection time was only 40 minutes, which the authors describe as a 56% improvement in speed compared with qPCR. The sample size is small, and the findings come from a brief report, so the clinical validation should be read as an initial demonstration rather than a large-scale performance evaluation.

The authors conclude that the ChronoGate RPA-CRISPR platform enables rapid, sensitive, and specific single-tube one-step detection with simple operation and high portability. In their framing, it provides a reliable point-of-care testing solution for monkeypox virus and potentially other pathogens in resource-limited settings, where the laboratory infrastructure required for qPCR is often unavailable.

More broadly, the work illustrates how material properties can be used to choreograph molecular reactions. By exploiting the temperature-dependent gel-sol transition of poloxamer, the platform converts a timing problem—when should detection start relative to amplification—into a physical barrier that dissolves on cue. If the approach generalises to other pathogen targets, it could simplify the design of closed-tube CRISPR diagnostics that retain two-step sensitivity without two-step handling, a persistent trade-off in the development of field-deployable nucleic acid tests.

Subject of Research: A one-step RPA–CRISPR/Cas12a point-of-care detection platform using poloxamer-mediated temporal-spatial separation for monkeypox virus testing

Article Title: Development of a one-step RPA–CRISPR/Cas12a point-of-care detection platform based on poloxamer-mediated temporal-spatial separation strategy and its application in monkeypox virus POCT

Article References: Liu, J., Ding, W., Zang, J., Bao, Y., Qu, Y., Zhu, J., Zhang, L., Ding, H., Han, R., Shen, Y., Xu, G., Shen, Q., & Sun, W. (2026). Development of a one-step RPA–CRISPR/Cas12a point-of-care detection platform based on poloxamer-mediated temporal-spatial separation strategy and its application in monkeypox virus POCT. Cellular & Molecular Biology Letters. https://doi.org/10.1186/s11658-026-01026-3

Image Credits: AI Generated

DOI: 10.1186/s11658-026-01026-3

Keywords: CRISPR/Cas12a, recombinase polymerase amplification, monkeypox virus, point-of-care testing, poloxamer, temporal-spatial separation, SHERLOCKv2, aerosol contamination, F3L gene, portable fluorescence detector, qPCR, resource-limited settings