Abstract: A single molecule of single-stranded sample DNA (7) having a bead (5) at one end and a magnetic bead (6) at the other end is extended and fixed in the field of view of a fluorescent microscope by using a magnetic force (11) and a laser trap (3), and a primer (8) is bonded thereto, followed by elongation reaction (10) using polymerase. Only a single chemically modified nucleotide (9) labeled with at least one fluorophore which varies depending on the kind of the base is incorporated. Only the single fluorophore incorporated is measured as a fluorescence-microscopic image by evanescent irradiation (13) with exciting laser beams, and the kind of the base is determined from the kind of the fluorophore. The fluorophore labeling the nucleotide incorporated is released by evanescent irradiation (13) with ultraviolet laser beams (2), and the next nucleotide is incorporated. DNA sequencing is carried out by repeating the above procedure.

Abstract: The inventive method for assaying DNA fragments in mixture comprises step 1 of ligating different oligomers hybridizable to primers of the same melting temperature and the same length to individual groups of DNA fragments in a set of DNA fragments; step 2 of mixing together the groups of DNA fragments ligated with the oligomers; step 3 of simultaneous PCR of the groups of DNA fragments ligated with the oligomers in one receptacle by using the primers being complementary to the oligomers and corresponding to the individual groups; and step 4 of detecting PCR amplified DNA fragments; characterized in that the method enables the comparison of plural samples under no influence of PCR reproducibility.

Abstract: Different probes each having a specific base sequence are immobilized to each of independent areas formed on the surface of a substrate, complementary polynucleotides in a sample solution are hybridized to the probes, and each of the independent areas on the substrate is heated and then cooled in sequence, and hence the solution is recovered to extract different polynucleotides separately corresponding to individual probes.

Abstract: There are beforehand prepared a monomer having a reaction residue and a polynucleotide probe set comprising plural kinds of polynucleotide probes having a residue bonded to the reaction residue. The monomer is mixed with each kind of polynucleotide probes comprising any plural probes selected from the polynucleotide probe set. Each kind of the resultant mixtures is added to each of different small holes to make the mixture into gel matrix. Thus, a polynucleotide probe chip is produced. Sample DNA is forcibly migrated in the gels by electrophoresis. Laser light is projected onto the side face of the chip. The fluorescence emitted from the whole surface of the chip is collectively detected with a high-sensitive two-dimensional detector. Thus, the polynucleotide probe chip, holding various kinds of DNA probes, for detecting DNA can be provided. This chip has high hybridization-efficiency and makes high-sensitivity and high-speed DNA detection possible.

Abstract: A single molecule of single-stranded sample DNA (7) having a bead (5) at one end and a magnetic bead (6) at the other end is extended and fixed in the field of view of a fluorescent microscope by using a magnetic force (11) and a laser trap (3), and a primer (8) is bonded thereto, followed by elongation reaction (10) using polymerase. Only a single chemically modified nucleotide (9) labeled with at least one fluorophore which varies depending on the kind of the base is incorporated. Only the single fluorophore incorporated is measured as a fluorescence-microscopic image by evanescent irradiation (13) with exciting laser beams, and the kind of the base is determined from the kind of the fluorophore. The fluorophore labeling the nucleotide incorporated is released by evanescent irradiation (13) with ultraviolet laser beams (2), and the next nucleotide is incorporated. DNA sequencing is carried out by repeating the above procedure.

Abstract: Different probes each having a specific base sequence are immobilized to each of independent areas formed on the surface of a substrate, complementary polynucleotides in a sample solution are hybridized to the probes, and each of the independent areas on the substrate is heated and then cooled in sequence, and hence the solution is recovered to extract different polynucleotides separately corresponding to individual probes.

Abstract: A kit and a method of DNA sequencing including digesting a sample DNA with a restriction enzyme to obtain a DNA fragment; introducing an oligonucleotide having a definite base sequence into the DNA fragment at the 3' terminus; and performing a complementary strand extension reaction, using a labeled primer. The complementary strand extension reaction uses as a template, a single strand of the DNA fragment having the oligonucleotide introduced thereinto, to obtain a labeled extended primer having a base sequence complementary to the single strand of the DNA fragment. Next a sequencing reaction with the labeled primer and using the single strand of the DNA fragment having the oligonucleotide introduced thereinto, is performed with the extended labeled primer, using as a template, a part of the single strand of the sample DNA having the base sequence of the single strand of the DNA fragment and a contiguous sequence adjacent thereto, or a single strand of the sample DNA.

Abstract: The present invention provides a DNA sequencing method comprising: (1) a step of fragmentation of a sample DNA and amplifying each fragment to obtain a first DNA fragment; (2) a step of obtaining from the first DNA fragment a second DNA fragment substantially complementary to the sample DNA at least at the 3' terminus thereof; and (3) a step of performing an extension reaction of complementary strand, using the sample DNA as a template to produce a third DNA fragment containing a base sequence complementary to the second DNA fragment and having a size longer than that of the second DNA fragment, and using the third DNA fragment as a template for sequencing of the sample DNA. DNA sequencing can be proceeded efficiently with extremely low redundancy.

Abstract: The method of base sequence determination according to the present invention ensures an effective determination of a long DNA base sequence, by providing simultaneous determination of base sequences of two or more positions of the long DNA or base sequences of two or more DNAs, using the DNA probe chip which classifies and retains the DNA oligomers having various sequences, and using fluorophorelabeled primers which have the same sequencies as the oligomers in the chip and are labeled by various fluorophores, then followed by the extension of the determined base length by re-selection of the primers complementary to the sequence thus determined.

Abstract: A method of analysis or assay for nucleotides comprises: (1) a step of digesting DNA with a restriction enzyme; (2) a step of discriminating a difference in sequences of the DNA fragments obtained in step (1) above around the 3' termini thereof with a DNA probe and extending the DNA probe by a complementary strand synthesis to fractionate the DNA fragments into groups; and, (3) a step of measuring lengths of the DNA fragments which belong to said groups, or length of the DNA probe extended by said complementary strand extension reaction; wherein the thus measured lengths obtained for every sequence of the bases of the DNA fragments around the 3' termini thereof are employed as fingerprints.

Abstract: A DNA analyzing method which bonds a first oligomer of known base sequence to a DNA fragment obtained by digesting a DNA sample with a restrictive enzyme. The oligomer and DNA fragment are hybridized to other oligomers which have the sequences of all combinations of the types of bases within the length of several bases following the known base sequence. The presence or absence of hybridization or complementary DNA strand extension is determined and identifies the DNA fragment terminal sequence from this result. The DNA fragments are then fractionated and analyzed to determine the sequence. This DNA analyzing method provides an effective analysis of mixtures of long DNAs or DNA fragments.

Abstract: A fractionation method for DNA fragments according to the present invention comprises a first step of preparing a probe chip or a set of probe chips immobilizing independently a DNA probe having a first sequence part having a specific known sequence part together with a part of enzyme recognition sequence and a second sequence part composed of a combination of one to six bases adjacent to the first sequence part at 3' terminus, a second step of introducing a DNA oligomer composed of a part of enzyme recognition sequence and a sequence complementary to the known sequence part into the fragment termini of DNA fragments from restriction enzyme cleavage, and a third step of placing the probe chip or the set of probe chips in a solution containing the nucleotide fragments with the introduced DNA oligomer produced at the second step, for at least hybridization and the complementary strand extension of the DNA probe, whereby the DNA fragments are fractionated.

Abstract: A polynucleotide capturing support for capturing, eluting and collecting a plurality of target polynucleotides in a sample solution. The polynucleotide capturing support includes a substrate having a plane surface and a plurality of cells which immobilize individually different probes complementary to a plurality of target polynucleotides, and form at different regions on said plane surface of said substrate. The support includes a plurality of first electrodes which supply an electric field to each of the cells. The first electrodes are capable of eluting the target polynucleotides hybridized to the probes from each of the cells individually. The support also includes a plurality of second electrodes arranged between the adjacent cells on the surface of the substrate, and an electrode field is supplied to each of the second electrodes.

Abstract: The method of base sequence determination according to the present invention ensures an effective determination of a long DNA base sequence, by providing simultaneous determination of base sequences of two or more positions of the long DNA or base sequences of two or more DNAs, using the DNA probe chip which classifies and retains the DNA oligomers having various sequences, and using fluorophorelabeled primers which have the same sequencies as the oligomers in the chip and are labeled by various fluorophores, then followed by the extension of the determined base length by re-selection of the primers complementary to the sequence thus determined.

Abstract: A DNA analyzing method comprising ligating the oligomer of a known base sequence to the DNA fragment obtained by digesting a sample with a restriction enzyme, hybridizing an oligomer and DNA fragment using oligomers which have the sequences of all combinations of the types of the bases within the length of several bases following the known base sequence, checking the presence or absence of hybridization or complementary DNA strand extension, identifying the DNA fragment terminal sequence from this result, and fractionating the DNA fragments and analyzing them. This DNA analyzing method provides an effective analysis of mixtures of long DNAs or DNA fragments.

Abstract: A method for simultaneously detecting a plurality of target polynucleotides in a sample on a single reaction chip and a method for separating a plurality of target polynucleotides are provided. On the reaction chip are arranged a plurality of independent cells for capturing different target polynucleotides. Different probes are immobilized onto the individual cells, and detect the cells where the target polynucleotides are captured, thereby analyzing the species of the captured target polynucleotides. Also, the individual cells function as electrodes to elute the captured target polynucleotides therethrough, thereby separating a plurality of the target polynucleotides.

Abstract: A method for simultaneously detecting a plurality of target polynucleotides in a sample on a single reaction chip and a method for separating a plurality of target polynucleotides are provided. On the reaction chip are arranged a plurality of independent cells for capturing different target polynucleotides. Different probes are immobilized onto the individual cells, and labeled probes detect the cells where the target polynucleotides are captured, thereby analyzing the species of the captured target polynucleotides. Also, the individual cells function as electrodes to elute the captured target polynucleotides therethrough, thereby separating a plurality of the target polynucleotides.

Abstract: DNA molecule length can be measured with high precision and efficiency by 1) using such means as electrophoresis gel migration to orient a DNA molecule having a fluorescence label at both its termini into a straight line by its passing through a migration path having in a portion of it an area not more than several micrometers in diameter, detecting the fluorescence label at both the termini at a predetermined location and measuring the interval between the detection of the fluorescence coming from one terminus and that of the fluorescence from the other or by 2) a DNA molecule bound to a fluorescence label at one terminus and to a particle at the other being led as a whole by such means as electric field application into an aperture smaller in diameter than the particle, leaving the particle fixed at the mouth of the aperture to stretch the DNA molecule and detecting the fluorescence position to measure the distance between the bound particle and the bound fluorescence label.

Abstract: A microparticle measuring method according to the present invention, by which the number of fluorescent microparticles is counted and the fluorescent microparticles are analyzed, includes the steps of introducing fluorescent microparticles into a narrow flow path almost one after another; irradiating the fluorescent microparticles in the narrow flow path with excitation light; detecting a signal pulse produced by detection of a single photon of fluorescence generated by the irradiation with the excitation light; and recognizing existence of the fluorescent microparticle, starting from the number of signal pulses measured per predetermined standard period, and further includes the step of obtaining the number of signal pulses per standard period with a time interval shorter than the standard period.

Abstract: This invention relates to an apparatus for two-dimensional electrophoresis which comprises a supporting plate fixed to a rotary axis, a support for first dimension electrophoresis disposed on the supporting plate and a support for second dimension electrophoresis disposed on another supporting plate. Both the supports are arranged in such a fashion that when the rotary axis is rotated, the support for the first dimension electrophoresis comes on the support for the second dimension electrophoresis or reaches a predetermined position in the support for the second dimension electrophoresis. This arrangement can shift the support for the first dimension electrophoresis to the support for the second dimension electrophoresis without damaging the former.