Anti-Acidic Mammalian Chitinase Rabbit Polyclonal Antibody

Frequently Asked Questions

What molecular weight should I expect for AMCase on a Western blot?

Human acidic mammalian chitinase (AMCase) migrates at approximately 50-52 kDa on reducing SDS-PAGE, though the predicted molecular weight from the 476-amino acid sequence is closer to 52.5 kDa. The enzyme undergoes N-glycosylation, which can shift the apparent mass slightly depending on cell type and post-translational modifications. If you're working with conditioned media or secreted fractions, expect a mature glycosylated form. Deglycosylation with PNGase F can help confirm identity if you observe heterogeneous banding. Always include a positive control lysate from lung or gastrointestinal epithelium where AMCase is abundantly expressed.

Does this antibody cross-react with mouse or rat AMCase?

This antibody is validated for human AMCase. Cross-reactivity with mouse or rat orthologs is not experimentally validated but may occur given the moderate sequence conservation of the chitinase catalytic domain across mammalian species. Human and mouse AMCase share approximately 60-65% amino acid identity. If you're working with rodent samples, we recommend treating this as a predicted cross-reactivity and verifying performance with a known positive control such as mouse lung lysate from IL-13-treated animals, where AMCase is upregulated. Titrate dilutions starting at 1:500 to 1:2000 for initial optimization.

What starting dilution should I use for Western blot with this AMCase antibody?

Start at 1:1000 in 5% non-fat milk or BSA in TBST for Western blot, as recommended. This dilution typically provides clean signal with low background for polyclonal antibodies in our chitinase portfolio. If your AMCase expression is low or you're working with non-lung tissues where endogenous levels are modest, try 1:500. Conversely, if background is high, dilute to 1:2000. Incubate overnight at 4°C for optimal epitope binding. We've generated this rabbit polyclonal against a large immunogen spanning most of the mature enzyme, so sensitivity is generally robust across denatured samples.

Can I use this antibody for immunohistochemistry on lung tissue?

Yes, Triple Point Biologics antibodies are validated for Western blot. Immunohistochemistry (IHC) and immunofluorescence (IF) validation is currently in progress. For AMCase detection in paraffin-embedded lung sections, standard antigen retrieval with citrate buffer (pH 6.0) at sub-boiling temperature typically works well. AMCase localizes primarily to bronchial and bronchiolar epithelium, with increased staining in asthmatic or allergen-challenged tissue where IL-13 drives expression. Start with a 1:100-1:200 dilution for IHC and include adjacent sections incubated with rabbit IgG as a negative control. Expect both cytoplasmic and secreted extracellular staining patterns depending on activation state.

What are good positive and negative control samples for AMCase Western blots?

Human lung epithelial cell lysates (primary or A549 line) serve as excellent positive controls, particularly if treated with IL-13 for 24-48 hours to induce AMCase expression. Gastric mucosa also expresses AMCase constitutively. For a negative control, use tissues with minimal chitinase expression such as liver, skeletal muscle, or brain lysate. If studying disease models, compare samples from allergen-challenged versus naive animals or tissue. Running recombinant human AMCase as a reference standard is ideal but not always accessible. Always verify loading with a housekeeping protein like beta-actin or GAPDH.

Does AMCase have isoforms or splice variants I should know about?

The CHIA gene encoding AMCase does not have well-characterized splice variants that significantly alter protein structure or antibody recognition. The primary transcript yields the 476-amino acid preproprotein, which undergoes signal peptide cleavage to generate the mature secreted enzyme. Some databases list minor transcript variants, but these have not been validated at the protein level. You should observe a single predominant band around 50-52 kDa under standard conditions. If you see multiple bands, consider glycosylation heterogeneity, proteolytic processing in certain tissue contexts, or non-specific binding requiring further optimization of blocking and dilution conditions.

How should I store this AMCase antibody and what is the shelf life?

Store the antibody at -20°C in small aliquots to avoid repeated freeze-thaw cycles, which can compromise polyclonal antibody performance over time. The 100 µg pack size is supplied in a stabilization buffer; check the product datasheet for specific formulation details such as glycerol content, which affects freezing behavior. Under these conditions, the antibody typically remains stable for at least 12 months from date of receipt. Once thawed, an aliquot can be stored at 4°C for up to one month if you're using it frequently. Avoid prolonged exposure to room temperature and never refreeze a working aliquot.

Will this antibody detect AMCase enzymatic activity or only protein presence?

This is an immunological reagent that detects AMCase protein by epitope recognition, not enzymatic activity. It will bind both active and inactive forms of the enzyme, including catalytically dead mutants or improperly folded protein. If your research question centers on functional chitinase activity rather than expression levels, you'll need a separate enzymatic assay using fluorogenic chitin substrates like 4-methylumbelliferyl chitotriose. The antibody is valuable for confirming AMCase localization, quantifying expression changes in response to stimuli like IL-13, or detecting the protein in tissue lysates where activity assays may be confounded by other chitinase family members.