Abstract: The present invention provides a method of detecting a fluid surface and a circuit for an ultrasonic transducer for detecting such a fluid surface. In accordance with the method, an ultrasonic transducer driver generates a first voltage proportional to the resonant frequency of the ultrasonic transducer. A reference voltage is generated and the reference voltage and the first voltage are monitored and compared, and a surface detect signal is generated when the first voltage drops below the reference voltage. The circuit of the invention includes means for generating a first voltage proportional to the resonant frequency of the transducer, means for generating a reference voltage, and a comparator for monitoring the first and reference voltages and generating a surface detect signal when the first voltage drops below the reference voltage.

Abstract: Peptides are disclosed possessing some of the immunological properties of the peptide of the formula Gly-Gly-Arg-Leu or Lys-Lys-Thr-Glu, as well as application thereof for screening for certain autoimmune diseases.

Abstract: Peptides comprising between 20 and 39 amino acids capable of reacting with antibodies against the Sm-D polypeptide. These peptides may be used in a diagnostic method to detect of antibodies against the Sm-D polypeptide in a biological sample from a person suffering from systemic lupus erythematosus.

Abstract: The present invention provides an analyzer which permits clinical analysis of samples for multiple analytes with a variety of assay protocols in a multiple chronology sequence while operating on a predetermined fizzed length cycle method of timing control. In this analyzer, assay resources (e.g. an incubator belt, a wash station, and a signal detection apparatus) are assigned fixed operating sequences which begin and end within a time cycle of fixed duration. Samples may be transferred directly from one assay resource to another without unnecessarily occupying any unused resources. The invention also contemplates a method of analyzing samples consistent with use of this analyzer. In this method, different samples having different assay protocols may be entered into the analyzer. The assay resource requirements of the first sample are determined and "time slots" of the assay resources are allocated to that sample.

Abstract: The present invention relates to a process for determining or detecting by immuno adherence a biological substance present in a sample, which consists in introducing the sample into a receptacle on whose walls there is a component which has a specific immunological affinity for the substance to be tested for, in adding magnetic particles on which there is a substance which has a specific immunological affinity for the substance to be tested for, in subjecting them to several successive magnetic actions in order to accelerate the deposition of the said particles onto the walls and to displace those which have not formed specific bonds with the substance to be tested for which adheres to the walls via the component with affinity which is fixed thereto, and in observing the particles deposited.

Abstract: The invention includes an agglutinant complex which is useful for the investigation of the antigens present on erythrocytes, and which results from affinity couplings between nonagglutinant IgG type antibodies specific for the antigen to be identified, a protein capable of binding to at least two sites on the Fc part of antibodies and an anti-immunoglobulin antibody or its fragments.