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TSLP · Western blot design guide
Design a Western Blot for TSLP
Real validated TSLP Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-TSLP WB antibodies. Everything you need to plan the experiment before you commit precious samples.
Last reviewed: May 2026 · Scientific review: Boster Bio technical team
TSLP Western Blot Experimental Design Guide
Expected bands, validated protocols, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before running
| Expected band | ~18.1 kDa | |
| Gel | 12–15% | |
| Negative control | siRNA / KO lysate |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | Glycosylated + Cleaved | |
| Caveat | N-glycosylation adds mass | |
| Regulation | LPS-induced | |
| Isoform | 2 isoform(s) |
Section 1
Real Curated TSLP Western Blot Protocols
Literature-validated Western blot parameters for TSLP — gel percentage, transfer, blocking, antibody incubation and detection, extracted from published methods.
| Gel % | 12–15% |
| Transfer | nitrocellulose membrane, 150 mA, 50–90 min |
| Membrane | nitrocellulose |
| Blocking | 5% non-fat milk / TBS, 1.5 h RT |
| Primary antibody | 0.5 µg/mL |
| Primary incubation | overnight at 4 °C |
| Secondary antibody | goat anti-rabbit IgG-HRP, 1:5000 |
| Wash | TBS-0.1% Tween, 3 × 5 min |
| Detection | ECL |
| Exposure / imaging | Tanon 5200 |
| Observed band | 18 kDa |
Section 2
What Is the Expected TSLP Western Blot Band Size?
TSLP's 18.1 kDa precursor mass shifts upward in the secreted mature protein mainly due to N-glycosylation at two asparagine sites.
| Band running higher than the 18.1 kDa predicted mass, sometimes appearing diffuse | N-glycosylation at Asn64 and Asn119 adds carbohydrate mass and heterogeneity to the mature chain |
| Band smaller than the full 159-residue precursor size | Cleavage of the 28-residue N-terminal signal peptide removes mass to generate the secreted mature chain |
| No band, or only a faint band, in whole-cell lysate | TSLP is a secreted cytokine, so it is exported from the cell rather than retained intracellularly |
| An extra band at a different apparent molecular weight from the main band | The two annotated splice isoforms (1 and 2) can generate an additional species from alternative processing |
| Band migrates slightly faster (more compact) under non-reducing versus reducing conditions | The three intrachain disulfide bonds hold the folded protein in a compact conformation until reduced |
💡Expected TSLP appearanceExpect secreted, signal-peptide-cleaved mature TSLP to migrate above its calculated 18.1 kDa mass on a reducing gel, since N-glycosylation at two asparagine residues adds carbohydrate mass to the mature chain.
| Predicted mass (18.1 kDa, 159 aa precursor) | Sets the baseline unmodified backbone size before processing or glycosylation are accounted for |
| Signal peptide cleavage (residues 1-28) | Removes the N-terminal signal sequence so the secreted mature chain runs smaller than the full-length precursor |
| N-glycosylation at Asn64 and Asn119 | Adds carbohydrate mass and glycoform heterogeneity, shifting the mature band upward and sometimes broadening it |
| Splice isoforms 1 and 2 | Can generate an additional band at a qualitatively different apparent molecular weight from alternative exon usage |
| Three intrachain disulfide bonds | Stabilize a compact folded conformation that can make the non-reduced band migrate faster than the fully reduced band |
| Secreted extracellular localization | Means the protein accumulates in conditioned medium or serum rather than in whole-cell lysate |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | TSLP is a secreted cytokine that is exported out of the cell rather than retained intracellularly | Probe concentrated culture supernatant, conditioned medium, or serum/plasma instead of, or in addition to, whole-cell lysate |
| Band higher than expected | N-glycosylation at Asn64 and Asn119 adds carbohydrate mass above the 18.1 kDa predicted backbone | Treat the sample with PNGase F to deglycosylate and check for a shift back toward the predicted mass |
| Broad smear instead of sharp band | Heterogeneous glycan occupancy at the two N-glycosylation sites produces a range of glycoform masses | Run a lower-percentage gel for better resolution or deglycosylate the sample before loading to sharpen the band |
| Multiple bands | The two annotated splice isoforms, or incomplete versus complete signal-peptide processing, can produce species of different size | Compare against a mature-protein standard and confirm isoform identity by mass spec or an isoform-specific reagent if needed |
| Band lower than expected | Incomplete N-glycosylation or use of a non-glycosylated bacterially expressed recombinant standard can reduce apparent mass | Compare lysate bands against a mammalian-expressed recombinant TSLP standard rather than a bacterial one |
| Weak or no signal | TSLP is a low-abundance secreted cytokine typically present at low baseline levels unless the tissue or cells are stimulated | Use a stimulus known to induce TSLP expression, concentrate conditioned medium, and increase total protein loaded |
Experiment evidence
Western blot images showing TSLP band
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for TSLP Western blot
🧪For positive controls for TSLP in Western blot, you can use recombinant TSLP protein or lysate from TSLP-overexpressing cells, since no reliable endogenous positive tissue is documented and native expression is typically low and stimulus-induced.
Positive control: TSLP-overexpressing cell lysate
Negative control: ubiquitously expressed; use siRNA knockdown or KO line
Loading controls: Run GAPDH, β-actin, and a total-protein stain (e.g. stain-free gel, Ponceau S, or REVERT) alongside TSLP blots as loading controls.
⚠️Feasibility: As a secreted, low-abundance cytokine with no HPA tissue data available, whole-cell lysates likely show minimal signal, so use conditioned medium or overexpression lysates and confirm specificity with siRNA knockdown or KO controls.
Comprehensive Human Protein Atlas IHC scoring per tissue. Rows are taken directly from the HPA tissue chart — click any row's HPA link to view the source.
Positive expression · recommended positive controls
| Tissue | Cell type | Level | Evidence | Source |
|---|
Undetected expression · recommended negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|
Section 3
Advanced TSLP Western Blot Tips
Deeper troubleshooting and optimisation questions for TSLP, answered from its protein features.
Why does TSLP run heavier than its 18.1 kDa prediction?
The 18.1 kDa value is for the unprocessed chain including the 1-28 signal peptide, which is cleaved before secretion. The mature secreted protein carries 2 N-glycosylation sites, so glycosylation typically offsets the loss of the signal peptide and pushes the observed band above the naive predicted mass.
Which isoform should the antibody detect on the blot?
UniProt lists 2 TSLP isoforms (isoform 1 and isoform 2). Confirm the immunogen sequence used to raise the antibody maps to the isoform you expect in your sample, since alternative splicing can shift apparent size or eliminate the epitope entirely in one isoform.
Does glycosylation explain a diffuse or smeared band?
Yes. TSLP has 2 annotated glycosylation sites and no other listed modified residues, so N-linked glycans are the main source of heterogeneity. Treat the sample with PNGase F before loading to collapse a smeared band into a single sharp deglycosylated species for confirmation.
How should blocking be optimized for a glycoprotein cytokine?
Since TSLP is a secreted glycoprotein, milk-based blockers contain glycoproteins and lectins that can cause nonspecific background or interfere with glycan-sensitive antibodies. Use BSA-based blocking buffer instead, and extend blocking time given TSLP's low endogenous abundance in most tissue lysates.
What transfer method to use for TSLP Western blot?
TSLP is a small (~18 kDa) secreted protein, so use a high-percentage (12-15%) gel and a low-pore-size (0.2 um) PVDF membrane. Shorten wet or semi-dry transfer time relative to standard protocols to prevent this small protein from passing through the membrane.
How can TSLP be reliably quantified across samples?
Because TSLP is secreted rather than intracellular, normalize conditioned media or serum samples to total protein or loading volume rather than a housekeeping gene, which is invalid for supernatants. Given its low natural abundance, concentrate samples before loading for consistent quantitation.
Could disulfide bonds cause an unexpected higher band?
TSLP has 3 disulfide bonds. Under non-reducing conditions, these can stabilize dimers, aggregates, or the receptor-associated CRLF2/IL7R complex, producing bands well above the monomeric mass. Always run a fully reducing (DTT or beta-mercaptoethanol) sample in parallel to confirm the true monomer size.
Boster reagents
Best TSLP Western Blot Antibodies
BosterBio's TSLP antibodies are among the best-performing WB antibodies on the market — well cited, thoroughly validated, and orthogonally cross-validated against negative tissues and complementary methods.
Real WB data
Anti-TSLP Antibody Picoband®
Cat # A01096
Our recommended anti-TSLP antibody is a best-performing, extensively cited reagent, rigorously validated by Western blot and cross-checked against negative tissue and complementary detection methods for confident, reproducible TSLP detection.
Which to pick: Only one anti-TSLP antibody is listed, A01096, which includes an actual Western blot validation image using recombinant human TSLP protein, making it the clear, and only, choice for this application.
Source: BosterBio TSLP gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry Q969D9.
- Human Protein Atlas. TSLP tissue expression.