Microchip, nucleic acid extracting kit, and nucleic acid extracting method

A microchip for extracting nucleic acids, the microchip comprising:

• a first substrate;
• and
• a second substrate connected with the first substrate to define a connecting surface therebetween, the first substrate and the second substrate defining a microchannel in the connecting surface by a first groove part of the first substrate and a second groove part of the second substrate, the first groove part having a first protruding part and the second groove part having a second protruding part,
• wherein one of the first and second substrates includes a first inlet and a second inlet connected to the microchannel, the first inlet having received therein a first liquid containing microbeads, the second inlet having received therein a second liquid containing nucleic acid,
• wherein the microchannel includes a gap part formed by the first protruding part and the second protruding part, the gap part having a sectional size variable by a movable protruding part in the first groove part or in the second groove part, the movable protruding part being the first protruding part or the second protruding part, wherein, when the microchip is in use, the gap part is configured to block microbeads of a size greater than the sectional size of the gap part, and
• wherein the microchannel has an inner wall surface treated with triethylchlorosilane.