Abstract: A disposable indicator is disclosed which is useful for the measurement of ketones, proteins including albumin and uric acid in biological fluids. The instrument registers the concentration of substance in a given biological fluid with indicia which are directly readable in a convenient notation system (e.g., digital or other symbolic notation). The indicator comprises an improvement over prior art disposable devices which require a comparison of the viewable indication with a color intensity scale to translate the indicia registered to meaningful numerical values or other symbolic notations. The indicator permits the use of chemical reagent concentrations which are at least an order of magnitude greater than those used in prior art, thereby improving stability and drastically lowering the magnitude of interferences.

Abstract: A disposable indicator which is useful for the measurement of chemical substances in biological fluids. The instrument registers the concentration of substance in a given biological fluid with indicia which are directly readable in a convenient notation system (e.g., digital or other symbolic notation). The indicator comprises an improvement over prior art disposable devices which require a comparison of the viewable indication with a color intensity scale to translate the indicia registered to meaningful numerical values or other symbolic notations. The indicator permits the use of chemical reagent concentrations which are at least an order of magnitude greater than those used in prior art, thereby improving stability and drastically lowering the magnitude of interferences.

Abstract: A method is disclosed for isolating blood serum from clotted whole blood and for isolating blood plasma from mixtures of whole blood with anti-coagulants. The method comprises partially sinking an apparatus of the invention in the appropriate blood specimen, conveniently with the assistance of centrifugation.The apparatus of the invention comprises a hollow elongate body open at both ends. One end is partially closed with a filter member which prevents the passage of solid phase components of clotted whole blood and solid phase components of mixtures of blood with anti-coagulants but allows passage of blood serum or blood plasma.