Abstract: An instrument for measuring coagulation parameters is provided in which plasma and at least one reagent are mixed by spinning in a cuvette with transparent windows and in which measurement is then made of scatter by the mixture of the energy of a light beam sent into the mixture.Upon spin, the plasma components and reagent are displaced into the chamber, thus determining the initiation of the presence of the mixture in which the clot forms, and a photodetecting unit senses the change in the energy of the scattered light, caused by clot formation.

Abstract: Red cells are exposed to an unsaturated aldehyde such as acrolein (propenal) under conditions sufficient to increase the stability of the cells without impairing the ability of a lysing reagent to lyse the cells. After treatment, the treated cells are washed and are suspended in a stabilizing suspension medium.

Abstract: An assembly is shown over the top portion of the outer body 14 of a reference electrode or combination pH/reference electrode. An element 50 such as a turning ring covers the fill hole 16 through the outer body 14. In one position of the element 50, a sealing element 24 such as an O-ring forms a passage between fill hole 16 and a through hole 52 through element 50. In other positions of element 50, the sealing element 24 seals the fill hole 16. In embodiments shown, a housing 30 is integral with the cap assembly (60, 70) and aligns the sealing element 24 over the fill hole 16.

Abstract: A reagent complex is disclosed containing (1) a probe polynucleotide having a target binding region complementary to a target nucleotide sequence and (2) a signal strand polynucleotide bound by base pairing to a portion of the target binding region. The signal strand is displaced from the reagent complex by the target nucleotide sequence and separated from intact reagent complexes. A digestable ribonucleotide segment of the displaced signal strand, such as a 3' , terminal segment, is digested to ribonucleotide phosphates, which are phosphorylated to ATP. The ribonucleotide phosphates or ATP are detected.

Abstract: A diagnostic reagent is disclosed containing a complex of a probe polynucleotide (P) bound via purine/pyrimidine hydrogen bonding to a labeled polynucleotide (L). The probe (P) contains a target binding region (TBR) capable of binding to a target nucleotide sequence (G) of a biological sample. A method is disclosed in which contact with a sample containing the target nucleotide sequence (G) causes binding, initially between G and a single-stranded portion (IBR) of the target binding region (TBR). Thereafter the labeled polynucleotide (L) is displaced from the complex by branch migration of (G) into the (P)/(L) binding region. Determination of displaced labeled polynucleotide (L) gives a value which is a function of the presence and concentration of target nucleotide sequence (G) in the sample.

Abstract: A diagnostic reagent is disclosed containing a complex of a probe polynucleotide (P) bound via purine/pyrimidine hydrogen bonding to a labeled polynucleotide (L). The probe (P) contains a target binding region (TBR) capable of binding to a target nucleotide sequence (G) of a biological sample. A method is disclosed in which contact with a sample containing the target nucleotide sequence (G) causes binding, initially between G and a single-stranded portion (IBR) of the target binding region (TBR). Thereafter the labeled polynucleotide (L) is displaced from the complex by branch migration of (G) into the (P)/(L) binding region. A volume excluding polymeric agent such as poly(ethylene oxide) (PEO or PEG) or other polyethers enhances the rate of appearance of displaced labeled polynucleotide. Determination of displaced labeled polynucleotide (L) gives a value which is a function of the presence and concentration of target nucleotide sequence (G) in the sample.

Abstract: The concentration of a selected alkali metal cation in an aqueous sample is determined using an aqueous fill solution containing a dissolved polymeric cationic material (e.g., copper--PEI) and a dissolved fluorescent anionic material (e.g., ANS) and, in contact with the fill solution, an ionophore selective for the selected alkali metal cation. The aqueous fill solution is contacted with an aqueous sample through a membrane, the membrane being permeable to alkali metal cations, but impermeable to the polymeric cationic material. Fluorescence is detected either from molecules of fluorescent anionic material which have migrated from adjacent to the polymeric cationic material to adjacent to ionophore-complexed alkali metal cations or from molecules of fluorescent anionic material which have remained adjacent to the polymeric cationic material, or from both, especially through a fiber optic.

Abstract: Formulations of a cationic dye component (e.g., Azure A-Azure B-Azure C mixtures), an anionic dye component (e.g., Eosin Y) and an alcohol solvent (e.g., methanol or methanol-glycerol mixtures) are stabilized by an amino acid or its acid addition salt (e.g. lysine hydrochloride or glycine or a mixture of these).

Abstract: RNA such as messenger RNA is digested to nucleotide phosphates including AMP or ADP. The ATP or a byproduct of the phosphorylation, e.g., pyruvate, is detected. Exemplary enzymes used (with appropriate co-reactants and co-factors) are: (1) polynucleotide phosphorylase, pyruvate kinase and luciferase, or (2) phosphodiesterase (or RNase), myokinase, pyruvate kinase and luciferase. The phosphorylation to ATP (e.g., with pyruvate kinase) is preferably coupled with the previous (reversible) enzymatic step.

Abstract: Liquid is applied to a thin sample on a first surface (e.g., a specimen on a microscope slide) by maintaining a second surface parallel to the first to provide a gap therebetween and contacting an edge of the gap with a discrete aliquot of liquid. The liquid can migrate by capillary action into contact with the thin sample, preferably upward from horizontally extending linear edges of the surfaces. Liquid can also be removed by contacting the gap edges with absorbent material. Also disclosed are apparatus for holding a plurality of such surfaces in a vertically extending array and apparatus for holding a plurality of liquid droplets beneath the array. One apparatus can be moved relative to the other to contact the lower gap edges with droplets.

Abstract: A coupling arrangement between a hub and multi-cuvette rotor in analytical photometers, wherein the hub has a projection the section of which has a non-revolving profile and to such end comprises at least one rectilinear segment, the rotor designed for said hub featuring centrally a seating adapted to receive said projection on which hub, peripherally to said projection and distanced from the rectilinear-segment portion, there are arranged radially yieldable elastic elements provided with a portion which projects from said profile so that it elastically associates with the matching seating in the rotor.

Abstract: A target nucleotide sequence having a half-restriction site is determined in the nucleic acid of a biological sample. It is contacted with a reagent complex of:(i) a labeled probe polynucleotide containing a target binding region which is substantially complementary to the target nucleotide sequence and which contains a unique half-restriction site completely complementary to the half-restriction site of the target nucleotide sequence; and(ii) a second polynucleotide hybridized to the labeled probe polynucleotide in at least a portion of the target binding region, the portion including the unique half-restriction site of the target binding region;The second polynucleotide contains at least one mismatched or unpaired nucleotide opposite to the unique half-restriction site of the labeled probe polynucleotide, whereby a restriction enzyme specific for the unique restriction site will not cleave the reagent complex.

Abstract: Reagent complexes containing a probe polynucleotide with at least two target binding regions. A labeled polynucleotide is bound to at least a portion of each target binding region. In one method, sample nucleic acid displaces labeled polynucleotide from one target binding region; after washing, a reagent polynucleotide displaces labeled polynucleotide from the other target binding region. In a second method, sample nucleic acid strands having two target nucleic acid sequences in proximity (e.g., sequences translocated in certain cancers) displace the labeled polynucleotide from both target binding region.

Abstract: The present invention relates to aqueous perfluorocarbon emulsions and particularly microemulsions, and to their use as blood gas controls and calibrators.

Abstract: In an analytical photometer, in particular multi-channel, for the simultaneous analysis of a multiplicity of samples, the light source provided is a flash tube for producing light pulses in which a permanent preionization discharge is maintained and the light energy is derived by optical fibres to be sent to optical systems where the beam is divided into an analysis beam which travels through the sample and a reference beam, both finally delivered to photodetectors. Both the divided beams pass through identical filtering systems for selection of a narrow spectral band of relevance for analytical purposes.

Abstract: Competitive or inhibition assays are disclosed in which sample (e.g., containing target antigen), a reagent containing first particles (e.g., antibody-coated light particles) and a reagent containing second particles (e.g., antigen coated heavy particles) are reacted in a centrifugal field. Differential migration of first particles, of second particles and of first particles linked to second particles leaves a concentration of particles at a locus in solution after a time, which concentration is a function of the analyte concentration in the sample.

Abstract: A sample is mixed with a reagent containing stably suspended particles coated with a binding pair member complementary to or competitive with the target binding pair member. A centrifugal force applied during reaction is sufficient to change the concentration of particles at a locus relative to overall particle concentration. Light transmission or scattering is measured kinetically at the locus, especially in a microcentrifugal analyzer.

Abstract: Blood cells such as erythrocytes of animal origin are treated with a solution containing water, an organic cosolvent (such as dimethylsulfoxide, alone or admixed with a polyol), an aromatic polyaldehyde (such as phthaldialdehyde) and optionally salts and buffers. In an illustrative case, the treating solution is hypertonic and shrinks goat erythrocytes to the size of human platelets.