Abstract: The selection of oocytes has largely relied on manual procedures, resulting in their lack of uniformity. Groups of oocytes are prepared and sorted, the current responses of these groups of oocytes upon exposure to lysophosphatidic acid (LPA) are measured, the response of G protein-coupled receptor (GPCR) is determined for each group of oocytes, and desirable groups of oocytes are selected on the basis of the response of GPCR. In this way, oocytes having a uniformly high response of GPCR can be selected.

Abstract: This invention provides a method for assaying activities of signal transduction that enables identification of a ligand with a single assay method, thereby simplifying and accelerating the assay method for identifying a ligand of a GPCR with unknown functions. In this method, RNA encoding a GPCR and RNA encoding a chimeric Gq&agr; subunit constituted by a portion of a G11 or Gq subunit and a portion of a G14, G15, or G16 subunit are transfected together to an oocyte removed from a Xenopus and selected by a conventional technique. After transfection of the RNAs, a ligand candidate substance is added to the oocyte that was cultured for a given period of time, and the activity is then assayed.

Abstract: 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.

Abstract: An apparatus for microinjection of samples into amphibian oocytes, comprising a tray for holding a plurality of the amphibian oocytes, an injection needle for injecting a sample into the said amphibian oocytes, a driving means for moving a relative position between the said tray and the said injection needle and a controlling means for controlling the said movement by imputing a depth of the said injection needle for the said tray or the said amphibian oocytes in the injection of the sample, and injecting the sample into the said amphibian oocytes at the said depth.

Abstract: An apparatus for microinjection of samples into amphibian oocytes, comprising a tray for holding a plurality of the amphibian oocytes, an injection needle for injecting a sample into the said amphibian oocytes, a driving means for moving a relative position between the said tray and the said injection needle and a controlling means for controlling the said movement by imputing a depth of the said injection needle for the said tray or the said amphibian oocytes in the injection of the sample, and injecting the sample into the said amphibian oocytes at the said depth. According to the present invention, the sample can be injected into the amphibian oocyte with constant depth.precisely and quality of oocyte or a positional site of needle injection can be recorded as the information.

Abstract: 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 103 in the air is moved toward a Xenopus Oocyte 601 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 102 and the Xenopus Oocyte 601, and the sequence of electrophysiological measurement so as to penetrate the glass electrode 102 into the Xenopus Oocyte 601, hold the membrane potential and automatically administer the medicine.

Abstract: An apparatus for microinjection of samples into amphibian oocytes incorporates a tray for holding a plurality of the amphibian oocytes, an injection needle for injecting a sample into the amphibian oocytes, a driving means for moving a relative position between the tray and the injection needle and a controlling device for controlling the movement by inputting a depth of the injection needle for the tray or the amphibian oocytes in the injection of the sample, and injecting the sample into the amphibian oocytes at the given depth. According to the present invention, the sample can be injected into the amphibian oocyte with constant depth precisely , and quality of the oocytes and the positional site of needle injection can be recorded as information.

Abstract: 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.

Abstract: 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 103 in the air is moved toward a Xenopus Oocyte 601 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 102 and the Xenopus Oocyte 601 and the sequence of electrophysiological measurement so as to penetrate the glass electrode 102 into the Xenopus Oocyte 601, hold the membrane potential and automatically administer the medicine.

Abstract: 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.

Abstract: 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.

Abstract: Histamine may be quantitatively measured by providing the steps of: holding in a recess formed at the bottom of a vessel an oocyte that expresses histamine receptors, inserting first and second electrodes into the oocyte, measuring the membrane potential of the oocyte by means of said first electrode to stabilize the membrane potential of said oocyte at a predetermined level by driving a current through second electrode inserted into said oocyte by means of a circuitry for clamping membrane potential of oocyte, infusing a sample into a fine reacting tube having an antigen immobilized on the inner surface thereof together with some buffer solution to promote a histamine releasing reaction, transferring the solution containing histamine released in the fine reacting tube to the vessel to make contact with said oocyte in the vessel, detecting an electric response of oocyte caused by the contact with said solution, and determining the concentration of histamine released by said histamine releasing reaction in sai

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: 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.

Abstract: Histamine may be quantitatively measured by providing the steps of: holding in a recess formed at the bottom of a vessel an oocyte that expresses histamine receptors, inserting first and second electrodes into the oocyte, measuring the membrane potential of the oocyte by means of said first electrode to stabilize the membrane potential of said oocyte at a predetermined level by driving a current through second electrode inserted into said oocyte by means of a circuitry for clamping membrane potential of oocyte, infusing a sample into a fine reacting tube having an antigen immobilized on the inner surface thereof together with some buffer solution to promote a histamine releasing reaction, transferring the solution containing histamine released in the fine reacting tube to the vessel to make contact with said oocyte in the vessel, detecting an electric response of oocyte caused by the contact with said solution, and determining the concentration of histamine released by said histamine releasing reaction in sai

Abstract: 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.

Abstract: 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.

Abstract: 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.