A method of amplifying and/or detecting a target double-stranded nucleic acid, comprising: (a) combining a sample comprising the target double-stranded nucleic acid with an amplification reaction mixture, the amplification reaction mixture comprising: (i) an amplification CRISPR system, the amplification CRISPR system comprising a first and second CRISPR/Cas complex, the first CRISPR/Cas complex comprising a first CRISPR/Cas enzyme and a first guide molecule that guides the first CRISPR/Cas complex to a first strand of the target nucleic acid, and the second CRISPR/Cas complex comprising a second CRISPR/Cas enzyme and a second guide molecule that guides the second CRISPR/Cas complex to a second strand of the target nucleic acid; (ii) a helicase; (iii) a primer pair comprising a first and second primer, wherein the first primer comprises a portion that is complementary to the first strand of the target nucleic acid and the second primer comprises a portion that is complementary to the second strand of the target nucleic acid; and (iv) a polymerase; (b) amplifying the target nucleic acid by opening R-loops of the target nucleic acid using the first and second CRISPR/Cas complexes, unwinding the first and the second strand of the target nucleic acid using the helicase, annealing and extending the strands using the primer pair and the polymerase; and (c) further amplifying the target nucleic acid by repeated opening, unwinding, annealing and extension under isothermal conditions; and (d) optionally detecting the amplified target nucleic acid. (a) combining a sample comprising the target double-stranded nucleic acid with an amplification reaction mixture, the amplification reaction mixture comprising: (i) an amplification CRISPR system, the amplification CRISPR system comprising a first and second CRISPR/Cas complex, the first CRISPR/Cas complex comprising a first CRISPR/Cas enzyme and a first guide molecule that guides the first CRISPR/Cas complex to a first strand of the target nucleic acid, and the second CRISPR/Cas complex comprising a second CRISPR/Cas enzyme and a second guide molecule that guides the second CRISPR/Cas complex to a second strand of the target nucleic acid; (ii) a helicase; (iii) a primer pair comprising a first and second primer, wherein the first primer comprises a portion that is complementary to the first strand of the target nucleic acid and the second primer comprises a portion that is complementary to the second strand of the target nucleic acid; and (iv) a polymerase; (i) an amplification CRISPR system, the amplification CRISPR system comprising a first and second CRISPR/Cas complex, the first CRISPR/Cas complex comprising a first CRISPR/Cas enzyme and a first guide molecule that guides the first CRISPR/Cas complex to a first strand of the target nucleic acid, and the second CRISPR/Cas complex comprising a second CRISPR/Cas enzyme and a second guide molecule that guides the second CRISPR/Cas complex to a second strand of the target nucleic acid; (ii) a helicase; (iii) a primer pair comprising a first and second primer, wherein the first primer comprises a portion that is complementary to the first strand of the target nucleic acid and the second primer comprises a portion that is complementary to the second strand of the target nucleic acid; and (iv) a polymerase; (b) amplifying the target nucleic acid by opening R-loops of the target nucleic acid using the first and second CRISPR/Cas complexes, unwinding the first and the second strand of the target nucleic acid using the helicase, annealing and extending the strands using the primer pair and the polymerase; and (c) further amplifying the target nucleic acid by repeated opening, unwinding, annealing and extension under isothermal conditions; and (d) optionally detecting the amplified target nucleic acid.