Anti-TMPRSS-2 Rabbit Polyclonal Antibody

Frequently Asked Questions

What molecular weight band should I expect for TMPRSS2 on a Western blot?

Full-length TMPRSS2 runs at approximately 54 kDa, corresponding to the 492-residue transmembrane precursor. However, TMPRSS2 undergoes autocatalytic processing at the cell surface, generating a membrane-tethered non-catalytic fragment and a catalytic chain that remain associated. Depending on cell type and lysis conditions, you may observe the full-length band, processed fragments, or both. Glycosylation can shift apparent molecular weight upward. For initial experiments, scan the 40–70 kDa range. Positive controls such as LNCaP or Calu-3 lysates typically show robust signal at the expected sizes.

Does this TMPRSS2 antibody work for tissues other than prostate?

Yes. While TMPRSS2 is most abundant in prostate epithelium under androgen regulation, the protein is also expressed in respiratory, gastrointestinal, and urogenital epithelia. This antibody has been validated in human samples and is suitable for Western blot and IHC across these tissue types. Expression levels vary; lung epithelial cells such as Calu-3 or primary airway cultures are reliable positive controls. For IHC, antigen retrieval is typically required. If working with low-expression tissues, consider enriching membrane fractions or increasing sample load rather than exceeding the recommended dilution range.

What starting dilution should I use for Western blot with this TMPRSS2 antibody?

Start at 1:1000 in 5 percent non-fat milk or BSA in TBST for Western blot. This dilution is optimized for standard chemiluminescent detection with 20–40 µg total protein per lane. If your lysate has low TMPRSS2 expression or you are using colorimetric detection, try 1:500. Conversely, high-expressing samples such as LNCaP cells may yield clean signal at 1:2000. Titre against your specific lysate and detection system; the polyclonal format provides flexibility. Include a no-primary control to assess non-specific binding under your blocking conditions.

Is this antibody specific for human TMPRSS2 or does it cross-react with other species?

The antibody is validated for human TMPRSS2 and predicted to recognize monkey orthologs based on sequence conservation. Cross-reactivity with mouse or rat has not been confirmed; mammalian TMPRSS2 orthologs share substantial homology in the catalytic domain but diverge in linker regions. If working with non-human primates, test at the recommended dilution; expect comparable performance. For rodent samples, empirical testing is required and results are not guaranteed. Always include a species-matched positive control and verify band size against predicted molecular weight for the target ortholog.

What are good positive and negative control cell lines for TMPRSS2 Western blot?

LNCaP prostate carcinoma cells are a standard positive control; TMPRSS2 is highly expressed and androgen-responsive in this line. Calu-3 lung epithelial cells also express robust endogenous TMPRSS2 and are useful for respiratory research contexts. For a negative control, consider HEK293T or HeLa lysates, which show minimal or absent TMPRSS2 expression under standard culture. Verify your positive control by running a dilution series; strong signal at 1:1000 or higher confirms antibody performance. Negative controls help distinguish specific signal from cross-reactive or non-specific bands in your samples.

Can I use this TMPRSS2 antibody for immunofluorescence or cell-surface staining?

This rabbit polyclonal is validated for Western blot, but has not been formally tested for immunofluorescence or flow cytometry. Because TMPRSS2 is a type II transmembrane protein with a short cytoplasmic tail, surface staining without permeabilization is challenging and not recommended without pilot experiments. For IF on fixed, permeabilized cells, try 1:100–1:200 dilution; the extracellular and catalytic domains are more accessible after mild detergent treatment. Include a no-primary control and compare signal to a known TMPRSS2 IF reagent if available. Results will depend on fixation and epitope accessibility.

How should I store this TMPRSS2 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 titre and increase aggregation. The polyclonal format is supplied in a stabilized buffer; under these conditions, expect at least 12 months stability from date of receipt. Once thawed, an aliquot can be held at 4°C for up to one month for convenience during active experiments. Do not store diluted antibody; prepare working dilutions fresh for each experiment. If you observe increased background or decreased signal over time, prepare a fresh aliquot and compare performance.

Does androgen treatment affect TMPRSS2 detection in prostate cell lines?

Yes. TMPRSS2 is transcriptionally regulated by androgen receptor in prostate epithelium, and expression increases substantially upon androgen stimulation in AR-positive lines such as LNCaP or VCaP. If comparing androgen-treated versus depleted conditions, expect higher signal after DHT or testosterone treatment, typically peaking 24–48 hours post-induction. Use hormone-depleted serum and phenol red-free medium for at least 48 hours before androgen addition to minimize basal activity. This antibody will detect both basal and induced levels; normalize to loading control and consider biological replicate variation in androgen responsiveness.