AssayPro—Human Lysozyme ELISA

Introduction
Lysozyme is one of the anti-microbial agents found in human milk, and is also present in the spleen, lungs, kidneys, white blood cells, plasma, saliva, and tears. Lysozyme has 130 amino acids and its natural substrate is the bacterial cell wall peptidoglycan. Since it is synthesized by granulocytes and macrophages, lysozyme can act as a useful marker for myelomonocytic cells (1, 2). Increased levels of lysozyme in urine and serum are diagnostic indicators for acute monocytic leukemia and acute myelomonocytic leukemia (3). Elevated lysozyme levels were found in synovial fluids of the inflammatory arthritides and osteoarthritis (4). Human lysozyme gene mutations cause hereditary systemic amyloidosis (5, 6). The extracellular clusterin potently inhibits human lysozyme amyloid formation by interacting with prefibrillar species (7). Salivary lysozyme, a marker for oral infection and hyperglycemia, might display a significant relationship with hypertension, an early stage of cardiovascular disease (8).

Principle of the Assay
The AssayMax Human Lysozyme ELISA kit is designed for detection of lysozyme in human plasma, serum, urine, saliva, and cell culture supernatant. This assay employs a quantitative sandwich enzyme immunoassay technique that measures lysozyme in less than 4 hours. A polyclonal antibody specific for lysozyme has been pre-coated onto a microplate. Lysozyme in standards and samples is sandwiched by the immobilized antibody and biotinylated polyclonal antibody specific for lysozyme, which is recognized by a streptavidin-peroxidase conjugate. All unbound material is then washed away and a peroxidase enzyme substrate is added. The color development is stopped and the intensity of the color is measured.