Abstract: A method for producing a monoclonal antibody and antigen-specific antibody-producing hybridomas using a single antigen-specific B lymphocyte is provided. The method for producing antigen-specific antibody-producing hybridomas comprises selecting a single B lymphocyte reacting specifically with a certain antigen, an “antigen-specific B lymphocyte”, culturing the antigen-specific B lymphocyte selected, and fusing the cultured antigen-specific B lymphocyte with myeloma cells to obtain the hybridomas. The monoclonal antibody is produced with thus obtained hybridomas.

Abstract: A three-dimensional displacement gauge comprising a housing, a probe rotatably and slidably mounted on the housing, the probe is slidable along a first direction and having a contact member attached at one end thereof, two emitting members mounted on the probe each for emitting a light beam, two-dimensional measuring member such as a position sensor fixed to the housing for detecting the light beams, a biasing spring for biasing the probe toward the contact member, and a limit switch attached to the housing for detecting whether or not the probe moves in the first direction. The two-dimensional measuring member detects the light beams struck thereon so as to measure a small displacement of the contact member of the probe either in the first direction or in a second direction perpendicular to the first direction.