Table 2.

CRISPR-based assays for rapid detection of SARS-CoV-2

S. No.	Name of the kit/References	sgRNA target sequences/Cas system involved	Detection technology/Amplification method	Other details
1.	SHERLOCK by Sherlock Biosciences (Cambridge, USA)/ [57]	S and Orf1ab gene/Cas 13a (FDA approved)	Paper strip lateral flow-based detection/RPA	Both SHERLOCK and HUDSON techniques provide more sensitivity.
2.	DETECT by Mammoth Bioscience Inc. (California, USA)/ [57]	N and E gene/Cas 12a	UV or LED based detection/RT-LAMP	It detects SARS-CoV-2 within 30 minutes through lateral flow strip format.
3.	AIOD-CRISPR/ [57]	N gene/Cas 12a	UV or LED based detection/RPA	The ssDNA-FQ reporter is cleaved on binding of Cas12acrRNA to the target and produces fluorescence that is detected.
4.	CASdetec/ [59]	RdRp gene/3ʹDNA7 Cas 12a	Paper based detection/RAA	7-Nucleotide poly-T reporter is used as it gives better and more specific fluorescence signal.
5.	ENHANCE/ [57]	N gene/Cas 12b	UV or LED based detection/RT-LAMP	Lateral flow assay with FITC-ssDNA-Biotin reporter limits the detection time to 20 minutes.
6.	FELUDA/ [57]	Nsp8 and N gene/Cas 9a ortholog from Francisella novicida fnCAS9	Paper based detection/RPA	fnCAS9 shows high level of accuracy with significantly reduced off-targeting and faster detection.
Abbreviations: (a)SHERLOCK: Specific High-sensitivity Enzymatic Reporter un-LOCKing (b)DETECTR: DNA Endonuclease Targeted CRISPR Trans Reporter (c)AIOD-CRISPR: All-in-One Dual CRISPR (d)CASdetec: CRISPR-Cas12b-mediated DNA detection (e) ENHANCE: Enhanced analysis of nucleic acids with crRNA (CRISPR RNA) extensions (f) FELUDA: FNCAS9 Editor-Linked Uniform Detection Assay