Hitachi, Ltd.

Guohua Zhou

Hideki Kambara

Kazunori Okano

Masao Kamahori

Keiichi Nagai

Yuji Miyahara

The present invention provides a DNA base sequencing system having a compact, simple and convenient structure. In one embodiment of the present invention, a reaction chamber module for pyrosequencing in which a multiple number of reaction vessels (reaction chambers)and reagent-introducing narrow tubesare integrated is formed in a device board. Reagents held in reagent reservoirsandmounted separately from this reaction chamber module are introduced into the reaction vesselsvia reagent-introducing narrow tubes (capillaries). The reagent-introducing narrow tubes (capillaries)at the area of 2 cm from the reaction vesselsare structured with narrow capillaries having an inner diameter of about 0.1 mm and the conductance of these capillaries for the reagent solution determines the injection speed of the solution. Using the present invention, many kinds of DNAs can be analyzed simultaneously.

DNA base sequencing system

A method for examining nucleotide sequences of a sample includes adding a group of primers of multiple species to a solution containing the sample and simultaneously synthesizing complementary strands at each of the multiple regions containing the nucleotide sequences; designing the DNA probes with specific sequences elongate the complementary strands by the presence or absence of mutations in the nucleotide sequences, wherein the same number of such DNA probes and the nucleotide sequences are used for complementary strand synthesis; using the nucleotide sequences or their complementary sequences as a template to convert pyrophosphate produced during the elongation reaction to ATP which then reacts with chemiluminescent substrates to develop luminescence to be detected. According to the method, sensitivity is greatly increased by amplification of the amount of pyrophosphate produced in synthesis of the complementary strands without amplifying the copies of nucleotide sequences.

Method for testing nucleic acid sequence

To provide a method and an apparatus for detecting DNA mutation without using electrophoresis, the presence or absence of specific sequence is detected by a method comprising a step of serially hybridizing a 5-base-long to 8-base-long short oligomer , which is capable of being engaged in the complementary strand extension reaction, and a long oligomer , which is capable of hybridizing with a target DNA but incapable of being engaged in the complementary strand extension reaction, with the target DNA ; a step of carrying out the complementary strand extension reaction starting from the short primer using four kinds of nucleic acid substrates and polymerase; and a step of detecting photo-emission, in which pyrophosphate produced as a reaction by-product of the complementary strand extension reaction is converted into ATP and the photo-emission reaction is carried out using an enzyme.

Growing community of inventors

Koganei, Japan

Guohua Zhou