Myeloperoxidase, Human, Neutrophil (MPO, pANCA)

In normal tissues and in a variety of myeloproliferative disorders, myeloid cells of both neutrophilic and eosinophilic types, at all stages of maturation, exhibit strong cytoplasmic reactivity for MPO. It is readily detected in myeloblasts and immature myeloid cells of acute myelogenous leukemia, progranulocytic leukemia, monomyelocytic leukemia, erythro-leukemia, myeloblastomas, and other hematopoietic disorders. Erythroid precursors, megakaryocytes, lymphoid cells, mast cells, and plasma cells are nonreactive. Cells of monocytic derivation reveal variable reactivity and are typically weakly positive or nonreactive. Cells comprising the infiltrate of a spectrum of lymphoid malignancies, e.q., lymphoblastic lymphoma or leukemia, chronic lymphocytic leukemia, hairy cell leukemia, non-Hodgkin's lymphomas of T-or B-cell type, and Hodgkin's disease, are nonreactive, as are the non-neoplastic tissues present in these specimens, except for occasional cells of myeloid derivation. MPO is not observed in the neoplastic cells of a wide variety of epithelial tumors and sarcomas, or in the contiguous non-neoplastic tissues. MPO is useful in differentiating between myeloid and lymphoid leukemias. E.C.: 1.11.1.7, Activity: 180-220 units/mg protein after lyophilization. One unit is defined as the amount of enzyme that will decompose 1.0 micromole of hydrogen peroxide per minute at 25°C, pH 6.0. Storage and Stability: Lyophilized powder may be stored at -20°C. Stable for 6 months after receipt at -20°C. Reconstitute with sterile ddH2O. Aliquot to avoid repeated freezing and thawing. Store at -20°C. For maximum recovery of product, centrifuge the original vial after thawing and prior to removing the cap. Further dilutions can be made in assay buffer.