A TdT-driven amplification loop increases CRISPR-Cas12a DNA detection levels.
Biosens Bioelectron
; 261: 116464, 2024 Oct 01.
Article
em En
| MEDLINE
| ID: mdl-38861812
ABSTRACT
Recent findings on CRISPR-Cas enzymes with collateral DNAse/RNAse activity have led to new and innovative methods for pathogen detection. However, many CRISPR-Cas assays necessitate DNA pre-amplification to boost sensitivity, restricting their utility for point-of-care applications. Achieving higher sensitivity without DNA pre-amplification presents a significant challenge. In this study, we introduce a Terminal deoxynucleotidyl Transferase (TdT)-based amplification loop, creating a positive feedback mechanism within the CRISPR-Cas12a pathogen detection system. Upon recognizing pathogenic target DNA, Cas12a triggers trans-cleavage of a FRET reporter and a specific enhancer molecule oligonucleotide, indicated by the acronym POISER (Partial Or Incomplete Sites for crRNA recognition). POISER comprises half of a CRISPR-RNA recognition site, which is subsequently elongated by TdT enzymatic activity. This process, involving pathogen recognition-induced Cas12a cleavage and TdT elongation, results in a novel single-stranded DNA target. This target can subsequently be recognized by a POISER-specific crRNA, activating more Cas12a enzymes. Our study demonstrates that these POISER-cycles enhance the signal strength in fluorescent-based CRISPR-Cas12a assays. Although further refinement is desirable, POISER holds promise as a valuable tool for the detection of pathogens in point-of-care testing, surveillance, and environmental monitoring.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Técnicas Biossensoriais
/
Proteínas Associadas a CRISPR
/
Sistemas CRISPR-Cas
Limite:
Humans
Idioma:
En
Revista:
Biosens Bioelectron
Assunto da revista:
BIOTECNOLOGIA
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Holanda