An All-in-one Telomerase Assay Based On CRISPR-Cas12a Trans-cleavage While Telomere Synthesis

As one of the crucial factors associated with human life span and cancer progression,telomerase is regarded as an emerging biomarker for cancer diagnosis.Therefore,a facile,rapid and sensitive approach for telomerase activity detection with point-of-care(POC)diagnosis potential is in great demands.Herein,an all-in-one telomerase activity detection assay was established based on the telomere synthesis activated CRISPR-Cas12a system.A telomerase extension reaction generated telomere repeats sequences(TTAGGG)_n,which was recognized by a customized CRISPR-guided RNA(cr RNA)simultaneously,and finally activated a typical trans-cleavage-based CRISPR-Cas12a detection assay.With the inherent sensitivity of CRISPR-Cas12a,this approach achieved a great linear range from 100 to 2000 He La cells and a limitation of detection down to 26 He La cells.Moreover,by using the proposed method,telomerase can be detected in one pot under isothermal condition(37℃)by a simple and fast workflow(one step within one hour).Due to its excellent performance,this all-in-one method shows great potential in POC detection of the telomerase activity...