Abstract: Probe cocktails contain a nucleic acid probe and a sulfated polysaccharide as a volume excluding polymer to speed up hybridization rates. Exemplary sulfated polysaccharides are chondroitin sulfate A and C, which can be extracted from cartilage and similar tissues. Compared to synthetic anionic polymers such as dextran sulfate, the probe cocktails can have reduced viscosities and surface tensions, as well as reduced water loss when the cocktail is heated to denature DNA before rehybridization. The reduced viscosity and surface tension are of particular value when entering and exiting narrow spaces, as in some automated analyzers and in capillary gap methodologies.

Abstract: Compounds of the formula DNB-TZ(P2) (P3) X, wherein TZ is a tetrazolium ring, DNB is 5-(2,4-dinitrophenyl), X is halide and P2 and P3 are each independently halophenyl, nitrophenyl or phenyl. The compound INDT 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-(2,4-dinitrophenyl) tetrazolium bromide exhibits facile reduction to insoluble chromophoric formazan compared to the chromagen INT. INDT differs structurally from INT 2-(4-iodophenyl)-3-(4-nitrophenyl)-5-phenyltetrazolium chloride by having 2,4-dinitrophenyl instead of phenyl at the 5-position on the tetrazolium ring. The compounds, including INDT, are useful as chromagens for histological staining, as well as in enzyme-amplified staining as a part of immunological or hybridization assays.

Abstract: A thin sample on a surface such as a tissue specimen on a microscope slide is exposed to treatment liquid such as a stain, antibody of nucleic acid probe. The treatment is accelerated by exposing the treatment liquid on the surface to infrared radiation. A device is disclosed for placing such slides into a treatment chamber, for example as a plurality of slide pairs held vertically, with treatment liquid held in capillary gaps between each slide pair. An infrared radiation source provides radiation into the treatment chamber to accelerate the treatment of samples on such slide (on one or both surfaces facing each capillary gap) by the treatment liquid.

Abstract: Two rectangular slides having front and rear faces are held with front faces facing each other. Raised end portions on one or both front faces abut and space the front faces by a distance (e.g., 100 to 250 .mu.m) conducive for reversible capillary action between the slides. Raised island portions on one or both front faces are located at corners opposite the raised end portions. The raised island portions serve to maintain spacing between the front faces, particularly as the ends of the slides opposite to the raised end portions contact an absorbent material. An opening between the raised island portions permits liquid to enter and leave the gap between the front faces.

Abstract: A holder holding in fixed array:(a) a plurality of vertically-extending slides each having a vertically-extending face,(b) a plurality of vertically-extending cover members, each having a vertically-extending face, each face of a vertically-extending slide being spaced by a first distance less than 0.5 mm from a face of a vertically-extending cover member. The holder engages the vertically-extending slides and vertically-extending cover members adjacent to their upper ends in a fixed array with the sample face of each slide being a first distance from a substantially parallel face of a vertically-extending cover member. The lower edge of each slide extends horizontally and is spaced from a substantially parallel horizontally-extending lower edge of a cover member by the first distance. The space between the horizontally-extending lower edges is open.

Abstract: A device for holding a horizontal array of discrete aliquots of treating liquid having,(a) a horizontally-extending rigid base,(b) a horizontally-extending elastomeric member (or coating) on the horizontally-extending rigid base with a substantially planar horizontally-extending upper surface, and(c) a plurality of recesses formed in the elastomeric member, each recess opening to the horizontally-extending upper surface, the elastomeric member (or coating) having at its upper surface a material sufficiently incompatible with the treating liquid for a discrete aliquot of treating liquid in a recess to form a convex shape extending above the plane of the adjacent upper surface of the elastomeric member (or coating).

Abstract: A sheetlike object with a planar front face, a linear lower edge, a thickness about 0.5-5 mm and a raised pattern on a portion of the front face about 50-500 micrometers forwardly of the front face. For example, a rectangular microscope slide 25 mm wide, 75 mm high and 1 mm thick coated on one side by an adherent coating 50-500 micrometers thick. Two such slides with abutting coating portions of 50-125 micrometer thickness form a capillary gap between the remainder of the planar surfaces of 100-250 micrometer thickness. One such slide with a coating of 100-250 micrometer thickness forms a corresponding gap when placed against a flat (uncoated) slide. A similar raised portion is created by affixing a thin object (e.g., a 150 micrometer thick cover slip) to a portion of a microscope slide. Liquid is drawn into and out of the capillary gap by contacting the edge of the gap with liquids and then by absorbent.

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 method for detecting a minute quantity of an inorganic or organic target molecule by combining it with a composition of a detecting agent for the target molecule which carries, by direct or indirect means, a visualization polymer. The visualization polymer is composed of multiple units of a visualization monomer which are covalently linked together directly or indirectly covalently linked together by coupling agents which bond to chemical groups of the monomer. The monomer may be an enzyme, a tagged polypeptide, a tagged polyol, a tagged polyolefin or a tagged carbohydrate. The detecting agent may be an antibody, an enzyme, a lectin, strand of a DNA receptor protein, avidin, streptavidin and the like. The visualization polymer produces a high degree of amplification for the detection of the target molecule.