Abstract: The fertile period in a female can be detected by monitoring the calcium and magnesium concentrations in unstimulated saliva. In the three to five day period immediately prior to ovulation, the calcium and magnesium concentrations of saliva drop. This concentration monitoring can be done by any conventional means for quantitatively assaying calcium or magnesium, such as by flow through tests, test strips, cards, charts, probes, meters, and the like.

Abstract: Red blood cells are removed from whole blood or a fraction thereof by agglutinating whole blood with a mixture of a free agglutinating agent and nucleating particles having agglutinating agent intimately associated therewith to form clusters of red blood cells. High molecular weight polyethylene glycol may be added further to enhance agglutination. The clusters of red blood cells are much larger than the size of individual red blood cells, so that the clusters can easily be filtered through a porous medium. The plasma, which is substantially free of red blood cells, is further passed through a filter that optionally contains an additional agglutinating agent. Flow-delay additives may be provided to retain the fluid sample in contact with a reagent for a predetermined time.

Abstract: Water soluble salts of hydrazone compounds react quickly with aniline compounds in the presence of a peroxidase and hydrogen peroxide to provide a color which can be measured spectrophotometrically or visually, either in solution or when incorporated in a device for the measurement of analytes of interest. These water-soluble hydrazone salts are useful in determining hydrogen peroxide or an analyte which reacts to produce hydrogen peroxide in an aqueous liquid, by, in the presence of a substance having peroxidative activity, physically contacting a sample of a liquid with a dye-forming composition comprising a water-soluble salt of a hydrazone compound and a substituted or unsubstituted aniline compound to produce a colored dye; and detecting the dye formed as a result of the presence of hydrogen peroxide or an analyte which reacts to produce hydrogen peroxide.

Abstract: Red blood cells are removed from whole blood or a fraction thereof by contacting whole blood with a combination of an agglutinating agent and nucleating particles to form clusters of red blood cells. High molecular weight polyethylene glycol may be added further to enhance agglutination. The clusters of red blood cells are much larger than the size of individual red blood cells, so that the clusters can easily be filtered through a porous medium. The plasma which is substantially free of red blood cells is further passed through a filter that optionally contains an additional agglutinating agent. Flow-delay means may be provided to return the fluid sample in contact with a regard for a predetermined time.

Abstract: Red blood cells are removed from whole blood or a fraction thereof by contacting whole blood with a combination of an agglutinating agent and nucleating particles to form clusters of red blood cells. High molecular weight polyethylene glycol may be added further to enhance agglutination. The clusters of red blood cells are much larger than the size of individual red blood cells, so that the clusters can easily be filtered through a porous medium. The plasma which is substantially free of red blood cells is further passed through a filter that optionally contains an additional agglutinating agent.

Abstract: The invention describes biological assays in which hydrogen peroxide is used as an oxidizing agent, or wherein hydrogen peroxide is used to oxidize a dye or other intermediate to generate a detectable species. The stability of the hydrogen peroxide in the presence of at least one other enzyme which decomposes hydrogen peroxide is enhanced by the addition of a suitable inhibitor for the enzyme and the inhibitor does not substantially inhibit enzymes used in the assay. When catalase is the enzyme to be inhibited, catalase inhibitors that can be used in the biological systems include hydroxylamine sulfate. The enzyme inhibitor can be incorporated in an integral analytic device.

Abstract: A dye is covalently bound to a polymeric film, especially a polyhydric polymer, for assays and other purposes. The dye may be one which, when it comes into contact with hydrogen peroxide, changes color to indicate the presence of hydrogen peroxide. This dyed film may be used in qualitative or quantitative assays. This method chemically immobilizes dyes on support matrices with much higher yields of immobilized dye than has heretofore been possible. The covalently immobilized dye may be immobilized on solid matrix particles and combined with a free-flowing dye component to form a two component dye system. By combining a dyed film-former with a film-opener, the amount of dye available for assay is greatly enhanced. This provides a dye system which can be used to detect and measure quantitatively, accurately and precisely high levels of hydrogen peroxide. These high levels of hydrogen peroxide may result from the enzyme-mediated decomposition of various analytes from undiluted whole blood samples.

Abstract: A lancet device includes a body within which is slidably located a trigger and fixedly located a base. The base contains, in an armed position, the lance with its needle and a spring affixed to the lance. The trigger includes a mechanism to release the lance during use.In a preferred embodiment, the lancet device of the present invention is self-activated by the finger (or other body part) to be pierced. Depression of the trigger with the finger releases the lance and the spring so that the needle protrudes through an orifice in the end of the trigger and pierces the tissue. Because the spring is held in a pre-armed position, release of the spring is consistent, and reproducibility of incision is well controlled.

Abstract: A color-forming coupler is provided which can be used in test compositions, as well as methods and apparatus for detection of hydrogen peroxide. The color-forming coupler compounds react with a hydrazone or an aminoantypyrine in the presence of peroxidase and hydrogen peroxide to produce a darkly colored compound. In the presence of peroxidase and hydrogen peroxide, the couplers of the present invention react with a hydrazone or an aminoantipyrine to produce a deeply colored dye, which can be used to give a visual indication of the analyte present in the sample. These couplers can be used in diagnostic tests in which the analyte is converted to hydrogen peroxide. The color-forming couplers are N,N-disubstituted anilines of the formula shown in FIG. 1 , whereinR.sup.1 and/or R.sup.2 =H, C.sub.1 -C.sub.9 alkyl, C.sub.1 -C.sub.9 -C.sub.9 alkoxy, NR.sup.3 R.sup.4 (where R.sup.3 and/or R.sup.4 =H, C.sub.1 -C.sub.9 alkyl, aryl, or heteroryl), F, Cl, Br, I, COOR.sup.5 (where R.sup.5 =H, C.sub.1 -C.sub.

Abstract: Sizing materials are applied to porous substrates to retain fluids in the substrate for a discrete period of time. After that time period, the fluid is substantially completely released from the porous substrate. Sizing materials include alkyl ketene dimers, fluorocarbon resins, and fatty acid chlorides.

Abstract: A quantitative test device is manufactured using a feedback loop which allows one to modify continuously the dimensions of a reading scale printed on the device. The quantitative test device is manufactured by attaching the critical component of a two-component dye system to minute particles such as microcrystalline cellulose, silica, or latex, which particles are suspended in a solution of a polymeric binder. Additional non-immobilized components of the reaction system of the test device are optionally added to the polymer solution. The suspension of dyed particles in polymer solution is applied to a fabric as a coating, using conventional coating machines, to obtain a homogeneous distribution of immobilized dye throughout the fabric.The device includes a measurement zone which is made from a film support made of a material having a lower melting point than the filter cloth fabric used in the measurement zone was used.

Abstract: Low density lipoproteins are directly determined in fluid samples by selectively precipitating low density lipoproteins from the sample by forming clusters, selectively consuming the high density and very low density lipoproteins, and resolubilizing the low density lipoproteins for direct determination thereof. The clusters are formed by treating the fluid sample with a mixture of a polyanionic compound, a divalent metal, and a nucleating agent. The clusters are redissolved and assayed for low density lipoproteins.

Abstract: Low density lipoprotein are directly determined in body fluids by selectively precipitating very low density lipoprotein, forming clusters with low density lipoproteins, selectively consuming the high density lipoproteins, and resolubilizing the low density lipoproteins for direct determination thereof. The clusters are formed by treating the fluid sample with a mixture of a polyanionic compound, a divalent metal, and a nucleating agent.

Abstract: An analytical device for fluid samples includes a fluid sample well means connected to a sample initiation area in such a fashion that the assay will not commence unless sufficient sample is introduced into the sample well means to conduct the assay. Once sufficient sample has been deposited into the sample well means, the sample flows into an initiation area and the assay commences.

Abstract: The invention is a self-contained, chromatic quantitative analyzer that quantitatively detects an analyte in a biological fluid. The invention includes a base having a first open reservoir for receiving the biological fluid. A means for separating solids from the biological fluid is provided in the first open reservoir. A channel is provided which draws, by capillary and/or wicking action, the biological fluid from the first open reservoir to a second open reservoir. The second open reservoir draws the biological fluid from the channel and, when the second open reservoir is full with the biological fluid, the capillary and/or wicking action terminates. A membrane is provided in the channel which is permeable to the biological fluid. There is at least one chromatic chemical indicator immobilized in the membrane in a predetermined concentration. The membrane enables the biological fluid to interact with the chromatic chemical indicator.