Abstract: A reaction kit is provided with a reaction zone of suitable cross-sectional area to aspirate a sample by capillarity and a transparent plate with a flat surface in at least part of the reaction zone, and a supporting base to incline the reaction zone at a specified angle. The reaction zone is normally a space formed by two opposite transparent plates and spacers inserted between these two transparent plates. A supporting base may be molded separately, the transparent plates and spacers being set on the base at the time of measurement, or alternatively the base may be molded integrally with at least one of the plates defining the reaction zone. Further, substances with specificity such as antigens or antibodies may be coated on a surface in the reaction zone.

Abstract: A reaction apparatus with sample inlet channel of suitable cross-sectional area for aspirating a sample into the interior of the apparatus by capillarity, a recess provided on the inner wall of the sample inlet channel, and a transparent plate with a flat surface arranged opposite the recess. The recess has sloping walls, and may for example, have a conical or hemispherical form. The recess may moreover be a V-shaped or U-shaped groove. Further, the inner wall of the recess may be coated with antibodies or antigens.

Abstract: A device and a method for fusing biological cells. The device is formed by a chamber having a tube for containing a cell suspension and a cover for sealing the tube. The chamber is provided with a lower electrode having a smooth and flat surface for contacting the cells precipitating in the cell suspension, and an upper electrode opposite to the lower electrode. The lower electrode forms the inner bottom surface of the tube. The upper electrode is inserted in the cover to enter the tube. The chamber is centrifuged to form the layers of cells on the lower electrode at the bottom of the tube. Then, a predetermined ac voltage is applied across the upper and lower electrodes to fuse the cells efficiently. Such a device and method are useful for the production of monoclonal antibodies or giant cells.

Abstract: An immunoassay device and a method of performing immunoassay using this immunoassay device are disclosed. The immunoassay device includes a plate substrate having a flat surface, a plurality of adjacent projections projecting on the flat surface of the plate substrate, and a plurality of immunoreaction regions formed by applying and fixing immunoassay reagents to and in flat regions defined by the adjacent projections. The immunoreaction regions are spaced apart from each other and have surface levels equal to or higher than a surface level of the plate substrate. The immunoassay device is used to simultaneously perform various types of immunoassay and requires a simple washing for immunoassay. Specimens do not flow out from the plate or mix with each other, and safe, accurate immunoassay can be performed.