Abstract: A method for quantitatively measuring white blood cell (leukocyte) count and/or white blood cell (leukocyte) subsets count involves adding specific antibodies labeled with a marker to the biological fluid sample, capture of white blood cells from a fluid sample by a retainer, removal of other than leukocyte cells and other interfering substances by washing or using specific magnetic beads, and reading the result. The device for use in the present method includes a retainer for leukocyte cells and an absorption pad for taking up all excess washing solution flowing past the sample.

Abstract: An improved assay for detecting an analyte in a fluid sample includes a step of conducting a photochemical reaction, in which a substrate conversion catalyzed by a photosensitizer into a product of the photochemical reaction is temporary inhibited when the reaction mixture is irradiated with a light at a wavelength within a light absorption spectrum of the photosensitizer. The photosensitizer (or an enzyme to catalyze producing thereof) is attached to an entity having an affinity to the analyte, such entity is bound to the analyte prior to irradiation. To achieve temporary inhibition, certain additives are used such as ascorbic acid or its derivatives. The assay may increase the sensitivity of ELISA 20- to 100-fold.

Abstract: An improved assay for detecting an analyte in a fluid sample includes a step of conducting a photochemical reaction, in which a substrate conversion catalyzed by a photosensitizer into a product of the photochemical reaction is temporary inhibited when the reaction mixture is irradiated with a light at a wavelength within a light absorption spectrum of the photosensitizer. The photosensitizer (or an enzyme to catalyze producing thereof) is attached to an entity having an affinity to the analyte, such entity is bound to the analyte prior to irradiation. The assay may increase the sensitivity of ELISA 20- to 100-fold.

Abstract: A method for quantitatively measuring white blood cell (leukocyte) count and/or white blood cell (leukocyte) subsets count involves adding specific antibodies labeled with a marker to the biological fluid sample, capture of white blood cells from a fluid sample by a retainer, removal of other than leukocyte cells and other interfering substances by washing or using specific magnetic beads, and reading the result. The device for use in the present method includes a retainer for leukocyte cells and an absorption pad for taking up all excess washing solution flowing past the sample.

Abstract: Ultrasound-assisted particle agglutination assay methods and apparatuses are described based on first providing a standing wave ultrasound field at a resonance frequency of a test liquid in a resonator cell containing microparticles covered with a binding agent with high affinity to an analyte sought to be detected by the assay test. Formation of the specifically-bound and nonspecifically-bound aggregates of these microparticles is then followed by effective stirring of the liquid with swept-frequency sonication causing disintegration of nonspecifically-bound aggregates and leaving specifically-bound aggregates in place for further detection and measurement. The methods and devices of the invention allow significant improvement in the sensitivity and specificity of agglutination tests and are advantageously applicable to detecting various proteins, DNA, RNA and other biologically active substances. Specific examples are provided.

Abstract: Ultrasound-assisted particle agglutination assay methods and apparatuses are described based on first providing a standing wave ultrasound field at a resonance frequency of a test liquid in a resonator cell containing microparticles covered with a binding agent with high affinity to an analyte sought to be detected by the assay test. Formation of the specifically-bound and nonspecifically-bound aggregates of these microparticles is then followed by effective stirring of the liquid with swept-frequency sonication causing disintegration of nonspecifically-bound aggregates and leaving specifically-bound aggregates in place for further detection and measurement. The methods and devices of the invention allow significant improvement in the sensitivity and specificity of agglutination tests and are advantageously applicable to detecting various proteins, DNA, RNA and other biologically active substances. Specific examples are provided.