Abstract: A method for detecting a substance in a liquid sample involves precipitating a substance from the liquid sample and filtering it from the liquid sample. The precipitate is then tested for the substance of interest by contacting the precipitate with a dye that forms a visible reaction when exposed to the substance. A releasing agent may be used after filtering the precipitate and prior to testing the precipitate with a dye. In another embodiment, the sample is filtered without the prior use of a precipitating agent.

Abstract: A method for detecting a substance in a liquid sample involves precipitating a substance from the liquid sample and filtering it from the liquid sample. The precipitate is then tested for the substance of interest by contacting the precipitate with a dye that forms a visible reaction when exposed to the substance. A releasing agent may be used after filtering the precipitate and prior to testing the precipitate with a dye.

Abstract: A swab is impregnated with a test reagent such that a test for a specific substance can be effected by rubbing the impregnated swab over the surface to be tested and then viewing the swab for a reagent reaction. The swab may have a hollow stem, and within the hollow stem is a cartridge within another cartridge. An activator solution is in one of the cartridges and a reagent is in another of the cartridges. A method for testing for a substance includes impregnating a swab, and rubbing the swab over a surface suspected of containing the substance. If the substance is present in the surface, a reaction with the substance produces an easily detectable color on the swab tip.

Abstract: A method and apparatus for the detection of nutrients and contaminants in a liquid sample. The sample is added to a container which is then capped with a cap assembly which contains crushable reagent containers. As the cap is tightened, the crushable capsules release reagent which reacts with the substance to be detected, causing a detectable color change. The level of the substance in the sample correlates with the color change which can be quantitated by reading the reaction product in a spectrophotometer, or by comparing to known standards. The method is especially suitable for the detection of heavy metal contaminants such as lead, in drinking water.

Abstract: A method and apparatus for the detection of nutrients and contaminants in a liquid sample. The sample is added to a container which is then capped with a cap assembly which contains crushable reagent containers. As the cap is tightened, the crushable capsules release reagent which reacts with the substance to be detected, causing a detectable color change. The level of the substance in the sample correlates with the color change which can be quantitated by reading the reaction product in a spectrophotometer, or by comparing to known standards. The method is especially suitable for the detection of heavy metal contaminants such as lead, in drinking water.

Abstract: A method for detecting a substance in a liquid sample involving precipitating a substance from the liquid sample and filtering it from the liquid sample. The precipitate is then contacted by an oxidizing agent and tested for the substance of interest by contacting the precipitate with a dye that forms a visible reaction when exposed to the substance.

Abstract: A swab is impregnated with a test reagent such that a test for a specific substance can be effected by rubbing the impregnated swab over the surface to be tested and then viewing the swab for a reagent reaction. The swab may have a hollow stem, and within the hollow stem is a cartridge within another cartridge. An activator solution is in one of the cartridges and a reagent is in another of the cartridges. A method for testing for a substance includes impregnating a swab, and rubbing the swab over a surface suspected of containing the substance. If the substance is present in the surface, a reaction with the substance produces an easily detectable color on the swab tip.

Abstract: A swab is impregnated with a test reagent such that a test for a specific substance can be effected by rubbing the impregnated swab over the surface to be tested and then viewing the swab for a reagent reaction. A method for testing for a substance includes impregnating a swab with a reagent, and rubbing the swab over a surface suspected of containing the substance. If the substance is present in the surface, a reaction with the substance produces an easily detectable color on the swab tip.

Abstract: A swab is impregnated with a test reagent such that a test for a specific substance can be effected by rubbing the impregnated swab over the surface to be tested and then viewing the swab for a reagent reaction. A method for testing for a substance includes impregnating a swab with a reagent, and rubbing the swab over a surface suspected of containing the substance. If the substance is present in the surface, a reaction with the substance produces an easily detectable color on the swab tip.

Abstract: A swab is impregnated with a test reagent such that a test for a specific substance can be effected by rubbing the impregnated swab over the surface to be tested and then viewing the swab for a reagent reaction. A method for testing for a metal includes impregnating a swab with a reagent, such as, for example, a rhodizonate dye reagent when testing for lead, and rubbing the swab over a surface suspected of containing the metal. If a metal is present in the surface, a reaction with the metal produces an easily detectable color on the swab tip.

Abstract: A monoclonal hybridoma antibody with specificity for an antigen that is present on tumors of epithelial origin; the cell line secreting said antibodies; a process for selecting the cell line; a diagnostic process for detecting the antigen and a therapeutic process for neutrailization of the angtigen.

Abstract: Novel folic acid derivatives useful in processes for analysis of biological fluids for folic acid or its metabolites comprising components of the formula: ##STR1## wherein R is hydrogen or radioactive iodine.