Hitachi, Ltd.

Jun Otomo

Tomoko Takeshita

Shokichi Matsunami

Noboru Moriya

Sakae Saito

Sayuri Nomura

Hirokazu Kato

A method or an apparatus for selecting oocytes or eggs based on at least one objective criterion, such as membrane potential, comprises a step or means for selecting a plurality of oocytes or eggs having a certain size with a filter or the like, and a step or means for measuring a membrane potential of each of the oocytes or eggs thereby sorting out those with a membrane potential within a specified range. The selected oocytes or eggs are sold or transferred together with the measurement information or an injected sample of interest.

Apparatus and method for oocytes or eggs selection

Apparatus for microinjection of sample into amphibian oocytes

An automatic electrophysiological measuring apparatus to automatically penetrate a glass electrode(s) into the membrane of a Xenopus Oocyte to hold the membrane potential and to automatically measure reactions to the administration of a medicine is to be provided. A glass electrode in the air is moved toward a Xenopus Oocyte held in a cell. Changes in the potential states of the glass electrodes are picked up by a control computer to distinguish the relative positions of the glass electrode and the Xenopus Oocyte , and the sequence of electrophysiological measurement so as to penetrate the glass electrode into the Xenopus Oocyte , hold the membrane potential and automatically administer the medicine.

Automatic electrophysiological measuring apparatus/method

Automatic electrophysiological measuring apparatus / method

Histamine may be quantitatively measured by performing the following steps. First, an oocyte that expresses histamine receptors is held in a recess formed at the bottom of a vessel. Then, first and second electrodes are inserted into the oocyte. Subsequently, the membrane potential of the oocyte is measured by using the first electrode to stabilize this membrane potential at a predetermined level by driving a current through the second electrode using circuitry for clamping the membrane potential of the oocyte. A sample is then infused into a fine reacting tube having an antigen immobilized on its inner surface together with some buffer solution to promote a histamine releasing reaction. The solution containing histamines that is released in the fine reacting tube is transferred to the vessel to make contact with the oocyte in the vessel. Finally, an electric response of the oocyte caused by the contact with the solution is detected and the concentration of the histamine released in the histamine releasing reaction in the fine reacting tube is determined. The entire blood or mast cell suspension may be used as a sample without pretreatment.

Histamine measuring apparatus and a histamine measuring method

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Tokyo, Japan

Jun Otomo