Abstract: The invention relates to a method for amplifying specific nucleic acid fragments with the aid of two variants of a recurrent chain reaction 2/2 and 2/1, in which instead of the typical primers used in a standard PCR, the primers in the form of tandem repeated sequences of a singular (basic) primer, in which repeats are disposed according to a “head-to-tail” type, and which consist of two or more such elements, are used as forward and/or reverse primers. As a result of amplification, the length of an amplicon is increased with each cycle by the length of the singular primer, thereby increasing, over a cycle, annealing places in the amplicon, providing the growth of the coefficient of replication and bringing about the accelerated accumulation of the amplicons, the number of which is greater by several orders than said number in a PCR.

Abstract: The invention relates to a method for rapid detection of specific nucleic acid fragments with the aid of a PCR, consisting in amplifying target products in a special DNA thermocycler, provided with a special reaction thermal unit, which makes it possible to obtain, in reaction vessels in the form of standard polypropylene test tubes, a sloping temperature gradient directed at an angle to the direction of gravity. The amplification time is of 1-5 minutes. The inventive method can be recommended for DNA diagnostics, also field conditions, in medicine, veterinary sciences, in sanitary and epidemiological studies for detecting agents of dangerous infections, including potential bio-terrorist attacks, in criminalistics for identifying criminals in the food industry for detecting food products from genetically modified organisms, for testing raw material quality etc.