Anti-MMP-11 Rabbit Polyclonal Antibody

Frequently Asked Questions

What molecular weight band should I expect for MMP-11 on a Western blot?

MMP-11 migrates at approximately 51 kDa in its proenzyme form and around 44 kDa when activated. Because MMP-11 is not efficiently secreted in its active form and undergoes intracellular processing, you will typically detect the 51 kDa pro-MMP-11 band in cell lysates and conditioned media. In stromal fibroblast samples, the proform is predominant. If you observe multiple bands, consider that MMP-11 can be glycosylated, which may shift migration slightly. We recommend running a positive control lysate from MMP-11-expressing fibroblasts to confirm the expected pattern in your system.

What is the recommended starting dilution for this MMP-11 antibody in Western blot?

We recommend starting at 1:1000 dilution in blocking buffer for Western blot applications. This polyclonal antibody has been validated at this dilution in human samples. Depending on your expression levels and detection system sensitivity, you may need to optimize between 1:500 and 1:2000. MMP-11 is typically expressed at low levels by stromal fibroblasts rather than epithelial cells, so enriched stromal samples or longer exposure times may be necessary. Always include a no-primary-antibody control to assess background, and consider concentrating conditioned media if detecting secreted MMP-11.

Does this antibody work for mouse and rat MMP-11 detection?

This antibody has validated reactivity against human MMP-11 and predicted cross-reactivity with mouse and rat based on sequence homology. Human MMP-11 shares approximately 80 percent identity with mouse and rat orthologs, primarily in the catalytic and hemopexin domains where this polyclonal was likely raised. We recommend empirically testing the antibody at 1:1000 dilution in your rodent samples and running a human positive control in parallel. If signal is weak, titrate to 1:500. Cross-reactivity is not guaranteed without direct validation, so plan to include species-matched controls in your initial optimization experiments.

What sample types are best for detecting endogenous MMP-11 expression?

MMP-11 is expressed predominantly by stromal fibroblasts in tissues undergoing remodeling, not by epithelial cells, which distinguishes it from most other MMPs. For Western blot, fibroblast cultures, tumor stroma, or whole-tissue lysates enriched in connective tissue yield the strongest signal. Conditioned media from fibroblast cultures can also be used, though MMP-11 secretion is less efficient than other MMPs. For IHC, breast carcinoma stroma, wound-healing tissue, and fibrotic samples are positive controls. Avoid expecting robust signal in purely epithelial cell lines or lysates, as MMP-11 expression is typically absent or very low in those contexts.

Will this antibody detect both pro-MMP-11 and active MMP-11?

This polyclonal antibody is raised against a large fragment of MMP-11, likely spanning the catalytic domain, so it should recognize both the 51 kDa proenzyme and the 44 kDa active form. However, because MMP-11 is inefficiently activated and the proform is predominant in most biological samples, you will usually detect the 51 kDa band. Active MMP-11 may be present at low levels in specialized contexts such as tumor stroma or remodeling tissue. If you need to distinguish pro- from active forms, run reducing SDS-PAGE and compare migration to recombinant standards of known activation state.

What are appropriate positive and negative controls for MMP-11 experiments?

For positive controls, use lysates from primary human fibroblasts, particularly those stimulated with TGF-beta or cultured in three-dimensional collagen matrices, which upregulate MMP-11 expression. Tumor-associated fibroblast lines or breast carcinoma tissue lysates also work well. Recombinant human MMP-11 protein is a reliable standard for confirming antibody specificity and expected molecular weight. For negative controls, use epithelial cell lines with negligible MMP-11 expression or fibroblasts from MMP-11 knockout mice if available. A no-primary-antibody control lane is essential to rule out non-specific secondary antibody binding in your detection system.

How should I store this MMP-11 antibody and what is its stability after reconstitution?

Store the lyophilized antibody at minus twenty degrees Celsius until reconstitution. Once reconstituted in sterile phosphate-buffered saline or the buffer of your choice, aliquot immediately to avoid repeated freeze-thaw cycles and store aliquots at minus twenty or minus eighty degrees Celsius. Rabbit polyclonal antibodies targeting proteinases are generally stable for at least twelve months under these conditions. Avoid storing diluted working solutions; prepare fresh dilutions in blocking buffer for each experiment. If you observe reduced signal intensity or increased background over time, thaw a fresh aliquot rather than re-using a working stock. Do not store in frost-free freezers due to temperature cycling.

Why is MMP-11 substrate specificity different from other stromelysins?

MMP-11 exhibits restricted substrate specificity compared to stromelysins-1 and -2 and shows minimal activity against classical MMP substrates such as collagens, laminins, and fibronectin. This difference arises from structural features in its catalytic domain and inefficient activation by conventional proteinases. MMP-11 substrates include alpha-1-proteinase inhibitor and insulin-like growth factor binding proteins, suggesting a regulatory role rather than bulk extracellular matrix degradation. When interpreting MMP-11 expression data, consider that elevated levels may reflect stromal remodeling and signaling rather than direct matrix breakdown. This distinction is important for understanding its role in cancer progression and fibrosis.