The article introduces SHERLOCK, a CRISPR-based diagnostic platform that combines nucleic acid pre-amplification with CRISPR-Cas enzymology for specific recognition of DNA or RNA sequences. The platform, termed Specific High Sensitivity Enzymatic Reporter UnLOCKing (SHERLOCK), allows for multiplexed, portable, and ultra-sensitive detection of RNA or DNA from clinically relevant samples. The authors provide detailed step-by-step instructions for setting up SHERLOCK assays, including recombinase-mediated polymerase pre-amplification of DNA or RNA, and subsequent Cas13- or Cas12-mediated detection via fluorescent and colorimetric readouts, which provide results in less than 1 hour. They also include guidelines for designing efficient CRISPR RNA and isothermal amplification primers and discuss important considerations for multiplex and quantitative SHERLOCK detection assays. SHERLOCK is highlighted for its rapid, sensitive, and specific detection capabilities, making it suitable for various applications in clinical diagnostics and biotechnology.The article introduces SHERLOCK, a CRISPR-based diagnostic platform that combines nucleic acid pre-amplification with CRISPR-Cas enzymology for specific recognition of DNA or RNA sequences. The platform, termed Specific High Sensitivity Enzymatic Reporter UnLOCKing (SHERLOCK), allows for multiplexed, portable, and ultra-sensitive detection of RNA or DNA from clinically relevant samples. The authors provide detailed step-by-step instructions for setting up SHERLOCK assays, including recombinase-mediated polymerase pre-amplification of DNA or RNA, and subsequent Cas13- or Cas12-mediated detection via fluorescent and colorimetric readouts, which provide results in less than 1 hour. They also include guidelines for designing efficient CRISPR RNA and isothermal amplification primers and discuss important considerations for multiplex and quantitative SHERLOCK detection assays. SHERLOCK is highlighted for its rapid, sensitive, and specific detection capabilities, making it suitable for various applications in clinical diagnostics and biotechnology.