Abstract: The problem to be solved in the present invention is to provide a simplified and efficiently improved DNA recombination method. The above problem can be solved with the present method for preparing a recombinant DNA by inserting a DNA fragment of interest into a vector DNA, the method comprising the step of carrying out the following reactions at the same reacting location at the substantially simultaneouse time: (a) a reaction for simultaneously cleaving a site of the vector for inserting the fragment and a DNA containing the fragment in the presence of a restriction enzyme whose DNA recognition site and DNA cleavage site are discrete; and (b) a reaction for inserting the fragment into the vector in the presence of a DNA ligase.

Abstract: The present invention provides a method for determining the base sequence of a DNA. According to the method for determining the base sequence of a DNA of the present invention, a probe is used, which is a probe having a protruding end and identification-labeled according to the species of the base at the protruding end, containing a recognition sequence of a class IIS restriction enzyme, to carry out simultaneously in a chain reaction, for a plurality of DNAs to be analyzed, ligation of the end base of a DNA to be analyzed and a probe and cleavage of the end base of the DNA to be analyzed, allowing the base sequence to be determined sequentially by a single molecule spectrofluorimetry method, such that an effective determination of the base sequence of a DNA becomes possible.

Abstract: The present invention provides a method for determining the base sequence of a DNA. According to the method for determining the base sequence of a DNA of the present invention, a probe is used, which is a probe having a protruding end and identification-labeled according to the species of the base at the protruding end, containing a recognition sequence of a class IIS restriction enzyme, to carry out simultaneously in a chain reaction, for a plurality of DNAs to be analyzed, ligation of the end base of a DNA to be analyzed and a probe and cleavage of the end base of the DNA to be analyzed, allowing the base sequence to be determined sequentially by a single molecule spectrofluorimetry method, such that an effective determination of the base sequence of a DNA becomes possible.