A CASCADE NUCLEIC ACID AMPLIFICATION REACTION

摘要

A DNA template consisting of multiple tandem repetitions of an oligonucleotide unit is produced by stepwise copying of an oligonucleotide comprising at least one and a half units of a nucleotide sequence showing dyad symmetry by means of a template- and primer-dependent DNA polymerase in the presence of the necessary nucleoside triphosphates during repeated cycles of denaturation and annealing, or by endless copying of a circular oligonucleotide comprising at least one copy of said oligonucleotide unit by means of a nucleic acid polymerase, which is capable of strand displacement and is substantially without 5'-3' exonuclease activity, in the presence of the necessary nucleoside triphosphates and, if necessary, a primer capable of binding to some portion of the oligonucleotide, or by known reactions. Thereafter, in a cascade nucleic acid amplification reaction, a great number of partial and complete DNA or RNA copies of said DNA template is produced by means of a nucleic acid polymerase, which is capable of strand displacement and is substantially without 5'-3' exonuclease activity, by contacting the template with said nucleic acid polymerase in the presence of the necessary nucleoside triphosphates and, if necessary, a primer capable of binding to the oligonucleotide unit, the polymerase thus synthesizing DNA or RNA originating from, ideally, each repeating oligonucleotide unit in the DNA template. These reactions can be used in methods for detecting a target molecule or group and in processes for the amplification of a particular DNA sequence.