Abstract: A new surface immunoassay method is performed with two test surfaces. The method is used where serum samples may contain both an antibody for which it is desirable to test, and also competing sera constituents which may be present in indeterminate amounts. In accordance with the method, two different test surfaces are contacted with the same serum sample, and preferably the same aliquot of the serum. The first surface is treated to bind a broad spectrum of serum components including both the component to be tested for and also the competing components. The second surface is designed to bind the competing components but no substantial amount of the serum component to be tested for. The immunoassay is conducted with a labeled antibody, and quantitative measurement of the immunoassay is obtained by detecting the quantitative difference in the amount of labeled antibody on the two surfaces which have been subjected to the same serum sample.

Abstract: A combined test for quantitating immunoglobulin and identifying the presence of abnormal homogeneous immunoglobulin usually of myeloma origin. In a direct test, a first fraction of serum sample is adsorbed to a solid surface and the adsorbed immunoglobulin is reacted with labeled antibody and the quantity of labeled antibody on the surface is measured. A second fraction of the serum sample is subjected to a competitive test in which normal immunoglobulin is adsorbed onto a second solid surface. Then, specific labeled antibody is competitively immunologically reacted with the immunoglobulin adsorbed on the surface and sample immunoglobulin. After washing, the labeled antibody on the second surface is measured to provide a quantitative measurement of sample immunoglobulin. Abnormal immunoglobulin is indicated if the ratio of immunoglobulin content of the sample as found by the competitive test to the quantity found by the direct test is 2:1 or greater.

Abstract: A fluorometric system to determine the kind and amount of substances derived from a biological fluid (e.g., serum or urine) or tissue in which the substances to be detected (e.g., antigen, antibody, hormone or enzyme) are coated onto a substrate surface in fluorescent form. Multiple coating areas of different samples may be employed. The fluorometric system includes a source of filtered light to excite fluorescence, an optical system for conducting the excitation light to such coating, and optical systems for receiving emitted fluorescence and for detecting the same. The system efficiency and optical characteristics disclosed avoid photo-bleaching; limit fading; and are especially adapted to provide accurate surface reading fluorometry.

Abstract: A body suitable for use in the quantitative detection of an unknown quantity of a biologically derived sample suitably by radioimmunoassay, fluorometric detection, or by spectrophotometry. The body includes a handle attached to a nonparticulate, nonswellable, impermeable continuous surface region. A diagnostic reagent (e.g., an antibody) is covalently attached to the surface region. The surface region is stirred by the handle in a solution of sample substance (e.g., antigen) for reaction with the diagnostic reagent. In a competitive binding technique, a labelled substance (e.g., fluorochrome labelled antigen) is simultaneously contacted with the sample. Thereafter, the surface region is washed, and the label is measured as by a fluorometer. The technique is also applicable to the so-called "sandwich technique" in which the labelled substance (e.g., labelled antibody) is reacted with the sample substance after it has been reacted with the diagnostic reagent.

Abstract: Instructional apparatus employs a holding mechanism which has depressions in its upper surface of either one depth or different depths. A printed format containing pre-punched openings representing answer selections is disposed over the upper surface, and some or all of the openings are aligned with corresponding depressions. Sandwiched between the printed format and the upper surface is a highly elastic sheet of rubber-like material. The user pushes a rounded tip stylus through the selected opening and thence into the elastic sheet, and the degree of penetration by the stylus through the upper surface down into an underlying depression or hole indicates the correctness of the response and provides instantaneous feedback. Upon withdrawal of the stylus the elastic sheet returns to its former shape with no deformation; thus the apparatus may be used by many students without replacing formats or other used components.

Abstract: A fluorometric system to determine the kind and amount of substances derived from a biological fluid (e.g., serum or urine) or tissue in which the substances to be detected (e.g., antigen, antibody, hormone or enzyme) are coated onto a substrate surface in fluorescent form. Multiple coating areas of different samples may be employed. The fluorometric system includes a source of filtered light to excite fluorescence, optical systems for conducting the excitation light to such coating, and optical systems for receiving emitted fluorescence and for detecting the same. The system efficiency and optical characteristics disclosed avoid photo-bleaching; limit fading; and are especially adapted to provide accurate surface reading fluorometry.

Abstract: A fluorometric system to determine the kind and amount of substances derived from a biological fluid (e.g., serum or urine) or tissue. The substances to be detected (e.g., antigen, antibody, hormone or enzyme) is coated onto a substrate in fluorescent form. Multiple coating areas of different samples may be employed. The fluorometric system includes a source of light to excite fluorescence, a fiber optic cable to conduct the excitation light to such coating, and a second fiber optic cable to conduct emitted fluorescence to a detector device. The system minimizes any gap distance in the path from the sample to the detector which permits the loss of excessive fluorescence. A branched fiber optical cable with the main trunk terminating adjacent the sample with one branch for transmitting light to the sample and the other for transmitting fluorescence light to the detector.

Abstract: The invention relates to an instructional apparatus in which a holding mechanism has depressions in its upper surface of two different depths, means being provided to hold a printed format containing selected areas indicating answer choices on the upper surface of the holding mechanism. The selected areas in the format are arranged to align with the depressions and are defined by holes through the printed sheet. A blank response sheet is sandwiched between the printed format and the upper surface of the holding mechanism. The user pushes a stylus through the selected hole, and thence through the blank response sheet and into the underlying depression. If he has selected the correct answer the stylus will make a large hole in the blank sheet because the correct selections are above deep depressions whereas incorrect answer selections are above shallow depressions.

Abstract: This invention relates to a mathematical teaching aid comprising a beam which has two parallel longitudinal upper faces each face being divided up by equally spaced marks representing numbers, the numbers on one face progressing from 0 at one end to n at the other end of the beam face, the numbers on the other face progressing from 0 at the mid-point of the face to n/2 at one end and -(n/2) at the other end of the beam face.

Abstract: A multi-purpose mathematical aid designed to allow students, especially children, to see mathematical relationships by manipulation of materials. In its preferred form the mathematical aid comprises two moulded plates forming two halves of a storage case. Each plate has recessed square areas on one face for use with counting bars and catchment areas on the other face for use with disc or fractions of discs. The counting bars may, for example, be square or rectangular and may be adapted to rest in the recessed square areas.