Anti-TMPRSS4 Rabbit Polyclonal Antibody

Frequently Asked Questions

What band size should I expect for TMPRSS4 on Western blot?

TMPRSS4 runs at approximately 48–52 kDa on Western blot, corresponding to the full-length 437-residue type II transmembrane protease. The predicted molecular weight is ~48 kDa, but post-translational modifications including glycosylation can shift the apparent size upward. You may observe a doublet or diffuse band depending on the glycosylation state in your cell or tissue lysate. If you see bands near 25–30 kDa, these likely represent autocatalytic cleavage products, as TMPRSS4 undergoes activation cleavage releasing the extracellular serine protease domain. Always include a TMPRSS4-positive control lysate from pancreatic or colon epithelial cells.

What is the recommended starting dilution for TMPRSS4 antibody in Western blot?

Start at 1:1000 dilution for Western blot, which is the validated concentration for this rabbit polyclonal TMPRSS4 antibody. Depending on your target expression level and detection system sensitivity, you may titre between 1:500 and 1:2000. TMPRSS4 is moderately expressed in epithelial tissues; if working with low-abundance samples or whole-tissue lysates rather than epithelial-enriched fractions, begin at the more concentrated end. Use 5 percent non-fat dry milk or BSA in TBST for blocking. Incubate overnight at 4°C for optimal signal. Include a positive control such as pancreatic cancer cell lysate (e.g., PANC-1 or BxPC-3) to benchmark your signal.

Is this TMPRSS4 antibody specific to human or does it cross-react with mouse and rat?

This TMPRSS4 antibody is validated for human samples. Cross-reactivity with rat is predicted based on epitope homology, and pan-primate (non-human primate) and dog reactivity are also predicted but not experimentally confirmed. Mouse TMPRSS4 shares lower sequence identity in the immunogen region, so cross-reactivity is not expected. If you are working with rodent models, we recommend confirming reactivity by Western blot using a known TMPRSS4-positive rat or mouse tissue lysate, such as lung or intestinal epithelium, and comparing the band pattern to human controls. Always include species-matched negative controls to rule out non-specific binding.

Which tissues or cell lines are good positive controls for TMPRSS4 expression?

TMPRSS4 is highly expressed in gastrointestinal epithelium, pancreas, lung, and certain carcinomas. For Western blot or IHC positive controls, use pancreatic cancer cell lines such as PANC-1, BxPC-3, or AsPC-1, or colorectal cancer lines like SW480 or Caco-2. Normal human pancreas, colon, or gastric mucosa are also reliable tissue sources. TMPRSS4 is upregulated in many epithelial cancers, so metastatic or invasive tumor specimens often yield strong signal. Conversely, use TMPRSS4-negative cells such as fibroblasts or hematopoietic lines as negative controls to confirm antibody specificity and rule out off-target binding in your system.

Can I use this antibody for immunofluorescence or immunohistochemistry on TMPRSS4?

Yes, Triple Point Biologics antibodies are validated for immunofluorescence and immunohistochemistry in addition to Western blot. For IHC on formalin-fixed paraffin-embedded sections, perform antigen retrieval using citrate buffer (pH 6.0) or Tris-EDTA (pH 9.0) heat-induced epitope retrieval. Start at 1:100 to 1:200 dilution and optimize on your tissue type. For immunofluorescence on fixed or live cells, use 1:50 to 1:200 depending on expression level. TMPRSS4 localizes to the plasma membrane, so expect membranous and cytoplasmic staining patterns. Always include isotype or pre-immune serum controls to assess background binding.

How should I store the TMPRSS4 antibody and what is the shelf life?

Store the antibody at –20°C in small aliquots to avoid repeated freeze-thaw cycles, which can reduce titre and increase aggregation. The 100 µg pack size is suitable for aliquoting into 10–20 µL volumes depending on your typical experiment frequency. Once thawed, an aliquot can be kept at 4°C for up to two weeks; add sodium azide (0.02–0.05 percent final) as preservative if storing diluted antibody for longer periods. Do not store diluted antibody without preservative beyond a few days. Lyophilized or glycerol-stabilized formats have extended shelf life; consult the datasheet. Properly stored polyclonal antibodies remain stable for multiple years.

Does TMPRSS4 have splice isoforms that affect antibody detection?

TMPRSS4 has multiple annotated splice variants in UniProt, but the canonical isoform (Q9NRS4-1, 437 residues) is the predominant form in most tissues and cell lines. Alternative transcripts may encode truncated or domain-deleted proteins with altered membrane anchoring or catalytic activity. This polyclonal antibody is raised against a broad epitope spanning residues in the extracellular serine protease domain, so it should recognize most isoforms that retain this region. If you observe multiple bands on Western blot, consider that you may be detecting isoforms, cleavage products, or glycosylation heterogeneity. Consult RNA-seq or RT-PCR data from your tissue to predict isoform expression.

What sample preparation is recommended for detecting TMPRSS4 in cell lysates?

Use RIPA or Triton X-100 lysis buffer with protease inhibitor cocktail to extract TMPRSS4, which is a membrane-anchored protease. Include 1 mM PMSF or a serine protease inhibitor cocktail to prevent autocatalytic degradation during lysis. For cultured epithelial cells, harvest at 80–90 percent confluence; TMPRSS4 expression can vary with differentiation state. Load 20–40 µg total protein per lane for Western blot. If signal is weak, enrich membrane fractions by ultracentrifugation or use membrane protein extraction kits to concentrate TMPRSS4. Avoid boiling samples excessively, as aggregation of membrane proteins can occur; heating at 70°C for 10 minutes is often sufficient.