Sheep polyclonal antibody against human IgM, 1 mg. Specific for the µ heavy chain of human IgM. Sheep is the fourth host in the anti-human IgM family — goat cat. 321, mouse monoclonal cat. 445 and rabbit cat. 818 — and occupies the capture niche: sheep IgG separates cleanly from goat, mouse, rabbit and human IgG on Protein A/G columns and in cross-adsorbed secondary reagents, so a sheep-capture / goat- or mouse-detect sandwich avoids secondary-antibody binding to the capture arm, the most common false-positive failure mode in IgM immunoassays.
SPECIFICATIONS
Catalogue number: 898 | Host: Sheep | Target: Human
Target antigen: Human IgM (µ heavy chain)
Clonality: Polyclonal | Conjugate: Unconjugated
Specificity: Human IgM µ heavy chain
Format: IgG fraction | Package size: 1 mg
STORAGE / RECONSTITUTION
Ships at ambient temperature. Store 2 years at −20 °C or lower. After reconstitution or thawing, store at +4 °C for up to 4 weeks, or aliquot and freeze. Avoid repeated freeze-thaw.
APPLICATIONS
- IgM-capture (µ-capture) ELISA — coat cat. 898 on the plate to capture total IgM from serum, then reveal antigen-specific IgM with a labelled antigen or anti-antigen detection reagent. Because IgM is captured before antigen binding, competing IgG is washed away, eliminating the IgG-interference and rheumatoid-factor false positives inherent in direct-format IgM ELISAs.
- Capture antibody in IgM-specific sandwich ELISA — pairs cleanly with goat cat. 321 or mouse monoclonal cat. 445 on the detection arm.
- IgM-rheumatoid-factor (IgM-RF) immunoassay development.
- Total-IgM quantification ELISA for clinical chemistry, nephrology and immunodeficiency workups.
- Capture or immunoprecipitation of human IgM from serum, plasma or culture supernatant.
- Coating ligand for IgM affinity-purification columns.
- Western blot primary antibody for the human IgM µ chain.
- Substrate for in-house conjugation to HRP, AP, biotin or fluorophores.
APPLICATION HIGHLIGHTS — HIGH-VALUE RESEARCH NICHES
- Acute-versus-past infection serology — µ-capture kit development for early-window diagnosis (dengue, Zika, hepatitis A, measles, rubella, CMV, EBV, Toxoplasma, parvovirus B19, Lyme).
- Autoimmunity — IgM-RF and IgM autoantibody assay development.
- Immunodeficiency and B-cell biology — total-IgM quantification and IgM class-switch studies.
- Host-species orthogonality — sheep capture arm for multiplex or sandwich designs already using goat, mouse or rabbit reagents.
- Affinity purification — isolation of human IgM for standards and reference material.
