Abstract: A sample applicator for use in performing immunoassays comprises a tube defining an internal lumen and having a filter matrix at one end thereof. Sample is drawn into the applicator tube, either using a vacuum bulb or an automated assay device. The sample is filtered as it enters the tube, and is again filtered as it discharged from the tube in the opposite flow direction. By removing particulates from the liquid sample, assay performance can be greatly improved. The applicator may also comprise a reagent dispersed within a permeable matrix, which is useful for introducing reagent to a sample or other liquid assay component. As a liquid assay component is drawn into the applicator tube, the reagent is reconstituted by and mixed with the liquid, thereby reducing the number of steps required for the assay.

Abstract: An improved nebulizer for substantially complete discharge of liquid before "sputtering" occurs includes a housing having a mist outlet, and an aspirating structure including a nozzle having a base portion at one end thereof within the housing. The nozzle includes a nozzle outlet for discharge of gas under pressure within the housing at end of the nozzle opposite the base portion. The nebulizer further includes an inverted frusto-conical bottom wall disposed about the base portion of the nozzle away from the nozzle outlet, the bottom wall forming a liquid reservoir that drains towards the base portion of the nozzle. The aspirating structure also includes at least one passageway peripherally located with respect to the nozzle, the passageway communicating with the reservoir for aspiration of liquid from the reservoir in response to gas discharged from the nozzle to form a mist.

Abstract: A solid support "dipstick" immunoassay impregnated with sodium metaperiodate (NaIO.sub.4) is described wherein ascorbate interference with an assay having a peroxidase signal producing system is reduced or eliminated.