Abstract: Self-testing for a disease or physiological condition is achieved by having the individual being tested obtain a sample of physiological fluid, e.g., blood, urine, sputum or saliva, from him or herself. The sample is introduced into an assay system which produces a coded pattern indicative of the presence or a different coded pattern indicative of the absence of the disease or physiological condition. The individual then transmits the coded pattern to a remote location, for example by making a telephone call to an interpretation center, and receives from the remote location an interpretation of the coded pattern together with any counseling which may be appropriate in view of the interpretation of the coded pattern. The coded patterns are selected such that the individual may not interpret the test results without consulting the interpretation center.

Abstract: Rapid and accurate whole blood analysis measurements are made with analysis systems of the potentiometric type that employ restricted diffusion type liquid junctions where the whole blood sample is flowed past sensing electrode and liquid junction at a velocity of at least one centimeter per second during a data acquisition interval that is at least twenty-five milliseconds in duration.

Abstract: A clinical analyzer system flows a small volume (less than 200 microliters) of liquid sample to be analyzed from an inlet port past a sensor array to a series of analysis chambers. The sensor array includes two optical sensor units that are spaced a fixed distance apart, and each sensor unit transmits a beam of infrared radiation through the flow tube for sensing by a detector. Each detector output has a low value when blood is in the flow tube, an intermediate value when air is in the flow tube, and a high value when a clear liquid is in the flow tube. Control logic senses changes in the outputs of the detectors and accurately indicates gas-liquid interface transitions. The noninvasive system accurately locates leading and trailing edges of samples of biological fluids to be analyzed, monitors the integrity of those samples, and distinguishes between types of sample liquids processed by the analyzer.

Abstract: A blood gas control liquid comprises a stable oil-in-water emulsion that has an oxygen solubility coefficient of at least 10 ml O.sub.2 per 100 ml emulsion and a viscosity of less than 10 centipoises. The emulsion includes water, 5-40 percent by volume of a water-insoluble non-protein compound material, 0.25-10 percent by volume of a nonionic surfactant, a pH buffering agent and a preservative agent which is substantially non-reactive with the pH buffering agent. A preferred blood gas control liquid has a density of about 1.08. The blood gas control liquid has a pH in the range of 7-8, a partial pressure of carbon dioxide in the range of 15-80 millimeters Hg, and a partial pressure of oxygen in the range of 20-600 mm Hg.

Abstract: A fractionation system for providing a clarified fraction or a fraction for analysis of biological fluids and the like includes a disposable filtration vessel with a first reservoir chamber adapted to receive the fluid to be fractionated, a second reservoir chamber and a flow channel that extends between the reservoir chambers. The lower surface of the flow channel is defined by a microporous sheet membrane, and collection structure is disposed on the side of the membrane opposite the flow channel. Low gas pressure (less than ten psi) applied alternately to liquid surfaces in the reservoir chambers produced reciprocating flow of the fluid between the reservoir chambers in a wide thin stream through the flow channel with resulting collection of a fraction of the liquid material that passes through the membrane. A one-half milliliter volume of plasma from a two milliliter volume sample of blood is obtained with the system in less than one minute without any discernible hemolysis.

Abstract: A blood gas control liquid comprises water, 5-40 percent by volume of a water-insoluble perfluorinated compound material that has an oxygen solubility coefficient, at one atmosphere pressure, 25.degree. C., and a volumetric proportion of 15 percent of at least 10 ml O.sub.2 per 100 mL emulsion, 0.25-10 percent by volume of a nonionic, fluorocarbon-based surfactant, a preservative agent and a buffering agent which is substantially non-reactive with said preservative agent. The blood gas control liquid has a pH in the range of 7-8, a partial pressure of carbon dioxide in the range of 15-80 millimeters Hg, and a partial pressure of oxygen in the range of 20-600 mm Hg.