Disaccharides Protect Antigens from Drying-Induced Damage in Routinely Processed Tissue Sections.

Drying of the tissue section, partial or total, during immunostaining negatively affects both the staining of tissue antigens and the ability to remove previously deposited antibody layers, particularly during sequential rounds of de-staining and re-staining for multiple antigens. The cause is a progressive loss of the protein-associated water up to the removal of the non-freezable water, a step which abolishes the immunoavailability of the epitope. In order to describe and prevent these adverse effects, we tested, among other substances, sugars, which are known to protect unicellular organisms from freezing and dehydration, and stabilize drugs and reagents in solid state form in medical devices.

Epitope recognition in the human-pig comparison model on fixed and embedded material.

The conditions and the specificity by which an antibody binds to its target protein in routinely fixed and embedded tissues are unknown. Direct methods, such as staining in a knock-out animal or in vitro peptide scanning of the epitope, are costly and impractical. We aimed to elucidate antibody specificity and binding conditions using tissue staining and public genomic and immunological databases by comparing human and pig-the farmed mammal evolutionarily closest to humans besides apes.

A 2-Step Laemmli and Antigen Retrieval Method Improves Immunodetection.

Detection by immunohistochemistry of antigens relies on reproducibly optimal preanalytical and analytical variables such as fixation conditions, antigen retrieval (AR), and the resolutive power of the detection system. There is a need to improve immunodetection on routinely fixed and embedded material, particularly for scarcely represented but relevant antigens. We devised a 2-step method and applied it to a panel of antigens of common use for diagnosis, prognosis, individualized therapy use, or research.

Elution of High-affinity (>10-9 KD) Antibodies from Tissue Sections: Clues to the Molecular Mechanism and Use in Sequential Immunostaining.

Inconsistent results obtained with published methods for the elution of antibodies from tissue sections prompted the assessment of both old and new methods in combination with monoclonal rabbit antibodies of known, increased affinity (above 1×10(-9) KD). We tested an acidic (pH 2) glycine buffer, a 6 M urea hot buffer and a 2-Mercaptoethanol, SDS buffer (2-ME/SDS). Some antibodies were not removed by the glycine pH 2 or 6 M urea hot buffers, indicating that antibodies survive much harsher conditions than previously believed.