- DETECTR (DNA Endonuclease Targeted CRISPR Trans Reporter) is a CRISPR-based molecular diagnostic platform designed for the sensitive and specific detection of DNA sequences, particularly from pathogens and genetic markers.
- Developed by Jennifer Doudna’s team at the University of California, Berkeley, DETECTR utilizes the CRISPR-Cas12a system to recognize and cleave target DNA sequences, initiating a fluorescent or lateral flow-based readout. It is especially notable for its ability to function rapidly, at isothermal conditions, and without the need for complex laboratory infrastructure, making it highly suitable for point-of-care diagnostics.
- The core of DETECTR lies in the use of the Cas12a (formerly known as Cpf1) endonuclease, which is guided by a custom-designed CRISPR RNA (crRNA) to bind specific double-stranded DNA (dsDNA) targets. Upon successful target recognition, Cas12a undergoes a conformational change that activates a unique property: indiscriminate cleavage of nearby single-stranded DNA (ssDNA), a phenomenon known as collateral cleavage. DETECTR takes advantage of this collateral activity by incorporating a synthetic ssDNA reporter tagged with a fluorophore and a quencher. When Cas12a is activated by its target, it cleaves this reporter, separating the fluorophore from the quencher and producing a fluorescent signal detectable by basic laboratory or even field-deployable equipment.
- To enhance sensitivity, DETECTR often includes a pre-amplification step using recombinase polymerase amplification (RPA) or loop-mediated isothermal amplification (LAMP), which can be performed at a single, constant temperature. This avoids the need for thermal cycling as in PCR, thereby simplifying the procedure and making it feasible for low-resource environments. The combination of isothermal amplification and CRISPR-mediated detection enables DETECTR to detect extremely low quantities of DNA—often down to the femtomolar range—in less than an hour.
- One of DETECTR’s major applications has been in the rapid diagnosis of infectious diseases, including human papillomavirus (HPV), influenza, and most notably, SARS-CoV-2. The system can be adapted quickly for emerging pathogens by simply redesigning the guide RNA to match new target sequences. Furthermore, because of its high specificity, DETECTR can differentiate between closely related viral strains or detect single-nucleotide polymorphisms (SNPs), making it valuable for identifying mutations relevant to drug resistance or virulence.
- The DETECTR platform has also been adapted for use in lateral flow assays, enabling visual readouts without the need for specialized equipment. This advancement has transformed DETECTR into a practical tool for point-of-care testing (POCT) and home-based diagnostics, especially in outbreak settings or resource-limited regions. Overall, DETECTR represents a powerful fusion of CRISPR biology and molecular diagnostics, offering a rapid, accurate, and cost-effective alternative to traditional nucleic acid detection methods.
