Anti-Hemicentin-1 Rabbit Polyclonal Antibody

Frequently Asked Questions

What is the expected molecular weight for Hemicentin-1 on a Western blot?

Full-length Hemicentin-1 (HMCN1) has a predicted molecular weight of approximately 613 kDa based on its 5,635 amino acid sequence. However, due to extensive glycosylation and post-translational modifications typical of large extracellular matrix proteins, the apparent molecular weight often exceeds 650 kDa on SDS-PAGE. You may also observe lower molecular weight bands representing proteolytic fragments or splice variants, particularly in tissue lysates where matrix metalloproteinases are active. Running high-percentage acrylamide gels is not practical for this target; use 3-8% gradient gels with extended transfer times for optimal detection of the full-length protein.

What starting dilution should I use for Hemicentin-1 Western blot experiments?

We recommend starting at 1:1000 dilution for Western blot applications with this rabbit polyclonal antibody, as validated in our testing. Given that Hemicentin-1 is a relatively low-abundance extracellular matrix protein in most tissues, you may need to optimize toward more concentrated dilutions (1:500 to 1:750) depending on your sample type and expression levels. For basement membrane-rich tissues like kidney glomeruli or epithelial cell lysates, 1:1000 is typically sufficient. Always include a titration series with your first experiment, and ensure adequate protein loading (30-50 µg) to detect endogenous HMCN1 in non-overexpressing systems.

Does this antibody cross-react with mouse or rat Hemicentin-1?

This antibody has been validated for human Hemicentin-1. Cross-reactivity with mouse and rat orthologs is predicted based on sequence homology, as mammalian HMCN1 shares approximately 85-90% identity across these species, particularly in conserved immunoglobulin-like and EGF-like domain regions. However, we have not experimentally validated reactivity in mouse or rat samples. If you are working with rodent models, we recommend confirming specificity by testing lysates from knockout or knockdown controls if available, or by peptide competition assays. The large size and complex domain structure of Hemicentin-1 mean that epitope accessibility may vary across species.

What sample preparation is critical for detecting Hemicentin-1 in extracellular matrix?

Hemicentin-1 is an extracellular matrix glycoprotein localized to basement membranes, so standard cell lysis buffers may not efficiently extract it. For Western blot, use RIPA buffer supplemented with protease inhibitors and consider sequential extraction protocols: first extract soluble cytoplasmic proteins, then use harsher conditions (8M urea or SDS-containing buffers with boiling) to solubilize matrix-associated Hemicentin-1. For immunofluorescence or IHC on tissue sections, antigen retrieval is essential; citrate buffer (pH 6.0) heat-induced epitope retrieval typically works well for basement membrane proteins. Avoid over-digestion with proteases during tissue processing, as Hemicentin-1's large size makes it susceptible to fragmentation.

What positive control tissues or cell lines express high levels of Hemicentin-1?

Hemicentin-1 is enriched in tissues with prominent basement membranes. Kidney tissue, particularly glomeruli, serves as an excellent positive control due to HMCN1's role in podocyte function and glomerular basement membrane organization. Cardiac tissue also expresses Hemicentin-1, where it participates in fibroblast migration during remodeling. For cell lines, human podocyte cell lines or kidney epithelial cells (such as HK-2) typically show detectable expression. Embryonic tissues and trophoblast-derived cells may also express HMCN1 given its role in preimplantation development. Run these alongside your experimental samples to confirm antibody performance, especially when working with tissues where HMCN1 abundance is unknown.

Can this antibody distinguish between Hemicentin-1 and other fibulin family members?

Hemicentin-1 is also called Fibulin-6, but despite this nomenclature, it is structurally distinct from classical fibulins (Fibulin-1 through Fibulin-5) due to its much larger size and unique domain organization. This rabbit polyclonal was raised against Hemicentin-1-specific sequences and should not cross-react with other fibulin family members, which range from 50-80 kDa compared to HMCN1's 613 kDa predicted mass. The substantial molecular weight difference makes them easy to distinguish on Western blots. If you observe bands below 200 kDa, these are more likely proteolytic fragments of HMCN1 rather than other fibulins, though you can confirm specificity using siRNA knockdown or peptide competition assays.

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

Store the antibody at -20°C in single-use aliquots to avoid repeated freeze-thaw cycles, which can reduce titer and increase aggregation, particularly problematic for polyclonal sera. The 100 µg pack size is sufficient for approximately 100 Western blots at 1:1000 dilution; aliquot into 10-20 µL volumes based on your experimental throughput. Under these conditions, polyclonal antibodies typically remain stable for 12-24 months. Avoid storing in frost-free freezers where temperature cycling occurs. For long-term storage beyond two years, -80°C is preferable. If you notice increased background or reduced signal over time, this may indicate antibody degradation; compare performance against a freshly thawed aliquot to confirm.

Why am I seeing multiple bands on my Hemicentin-1 Western blot?

Multiple bands are common with Hemicentin-1 due to several factors. The full-length 613 kDa protein is susceptible to proteolytic cleavage by matrix metalloproteinases and other extracellular proteases, generating stable fragments that retain immunoreactivity. You may also detect splice variants or incompletely processed precursors. Differential glycosylation across tissues and cell types can cause mobility shifts and band broadening on gels. To minimize artifactual proteolysis, ensure you add broad-spectrum protease inhibitors immediately upon sample collection and work quickly on ice. If you need to confirm which bands represent genuine Hemicentin-1 species versus degradation products, compare fresh versus aged lysates or use metalloproteinase inhibitors during extraction.