Cat. No.
MABL-888
Application
RIA, therapeutic, FC, IF
Isotype
Engineer antibody
Species Reactivity
Human
Clone No.
M195
From
Recombinant Antibody
Specificity
This antibody binds CD33, which is a 67 kD glycoprotein expressed on monocytes, hematopoetic progenitors, early myeloid progenitor cells and myeloid leukemias (acute and chronic) but not expressed on mature myeloid cells, normal stem cells, other hemtopoietic cells and non hematopoietic human tissues.
Alternative Names
gp67; Siglec-3; Myeloid cell surface antigen CD33; Sialic acid-binding Ig- like lectin 3
UniProt
P20138
Immunogen
The original antibody was generated by immunizing mice with live leukemic myeloblasts.
Application Notes
This antibody is recommended for myeloid differentiation studies, diagnosis of acute non-lymphoid leukemia cells and therapeutic treatment of myelois leukemia. Specificity of this antibody to CD33 was determined using RIA and immunoabsorption. Immunoflurorescence assay showed that the antigen is not expressed on adult human tissues (PMID: 2716349). Flow cytometric analysis was used to confirm reactivity of M195 with fresh hematopoietic neoplasms in the blood or bone marrow. In combination with MY9, this antibody is useful in diagnosis of acute myelogenous leukemia(AML) (PMID: 2725060). Murine antibody M195 was used in the phase I trial of AML (PMID: 1999719). Humanized IgG1 and IgG3 versions of this antibody has higher apparent binding affinity for CD33 antigen than the chimeric and parent murine version (PMID: 1737932, 1458463). The increase in binding affinity resulted from eliminating an N-linked glycosylation site at residue 73 in the heavy chain variable region in the course of humanization (PMID: 8232322). Preliminary trials to treat AML with humanized antibody showed specific bone marrow targeting without an immunogenic response (PMID: 8124221).
Antibody First Published
Tanimoto et al. Restricted Expression of an Early Myeloid and Monocytic Cell Surface Antigen Defined by Monoclonal Antibody M195. Leukemia (1989); 3(5):339-48. PMID:2716349
Note on publication
Describes the restricted expression of a myeloid and monocytic cell surface antigen and its charaterization with this antibody.
Size
100 μg Purified antibody.
Concentration
1 mg/ml.
Purification
Protein A affinity purified
Buffer
PBS with 0.02% Proclin 300.
Storage Recommendation
Store at 4⁰C for up to 3 months. For longer storage, aliquot and store at - 20⁰C.
