This website uses cookies to ensure you get the best experience on our website.
- Table of Contents
UGT1A1 · Western blot design guide
Design a Western Blot for UGT1A1
Real validated UGT1A1 Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-UGT1A1 WB antibodies. Everything you need to plan the experiment before you commit precious samples.
Last reviewed: May 2026 · Scientific review: Boster Bio technical team
UGT1A1 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 | ~59.6 kDa | |
| Observed band | ~55 kDa | |
| Gel | 10–12% | |
| Negative control | siRNA / KO lysate |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | Glycosylated + Cleaved | |
| Caveat | N-glycosylation affects mobility | |
| Regulation | Not found in UniProt | |
| Isoform | 2 isoform(s) |
Section 1
Real Curated UGT1A1 Western Blot Protocols
Literature-validated Western blot parameters for UGT1A1 — gel percentage, transfer, blocking, antibody incubation and detection, extracted from published methods.
| Sample / lysate | human RT4 , Lane 2: human CACO-2 , Lane 3: rat liver , Lane 4: mouse liver . After electrophoresis, proteins were transferred to a nitrocellulose membrane at 150 mA for 50-90 minutes. Blocked the membrane with 5% non-fat milk/TBS for 1.5 hour at RT. The membrane was incubated with rabbit anti-UGT1A1 antigen affinity purified polyclonal antibody (A01865-1) at 0.5 μg/mL overnight at 4°C, then washed with TBS-0.1%Tween 3 times with 5 minutes each and probed with a goat anti-rabbit IgG-HRP secondary antibody (Catalog # BA1054) at a dilution of 1:5000 for 1.5 hour at RT. The signal is developed using an ECL Plus Western Blotting Substrate (Catalog # AR1196-200) with Tanon 5200 system. A specific band was detected for UGT1A1 at approximately 55 kDa. The expected band size for UGT1A1 is at 60 kDa |
| Gel % | 10–12% |
| Load | 30 ug |
| 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 | 55 kDa |
Section 2
What Is the Expected UGT1A1 Western Blot Band Size?
UGT1A1 has a 59.6 kDa predicted precursor but runs at approximately 55 kDa on blots, reflecting signal peptide cleavage and anomalous membrane-protein migration despite N-glycosylation.
| Single band around 55 kDa | the expected mature, glycosylated UGT1A1 monomer seen on most blots |
| Band running below the 59.6 kDa predicted precursor mass | loss of the 25-residue signal peptide plus faster-than-predicted migration typical of single-pass ER membrane proteins |
| Diffuse or smeared band rather than one sharp line | heterogeneous occupancy of the three N-glycosylation sites at Asn102, Asn295, and Asn347 produces a range of glycoform masses |
| Two bands close together | co-expression of the two annotated splice isoforms, which differ in length |
| Weak or absent band in cytosolic-only preparations | UGT1A1 is anchored in the ER membrane with a perinuclear distribution, so it is depleted from purely soluble cytosolic fractions |
💡Expected UGT1A1 appearanceExpect a single band at approximately 55 kDa for mature, glycosylated UGT1A1, running below its 59.6 kDa predicted precursor mass due to signal peptide cleavage and membrane-protein migration behavior.
| Predicted mass from UniProt, 59.6 kDa precursor | sets the theoretical starting point before any post-translational modification is considered |
| Signal peptide cleavage at residues 1-25 | removes the N-terminal signal sequence, lowering the mature protein mass below the 59.6 kDa precursor prediction |
| N-glycosylation at Asn102, Asn295, and Asn347 | adds carbohydrate mass and heterogeneity, broadening or slightly raising the band relative to the unmodified backbone |
| Single-pass ER membrane topology | hydrophobic membrane-associated regions bind SDS atypically, causing the mature glycoprotein to migrate faster than its calculated mass, near the observed 55 kDa band |
| Splice isoforms 1 and 2 | can produce an additional band at a different apparent size when both isoforms are expressed, though no isoform-specific mass is defined |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | UGT1A1 is enriched in ER microsomal membranes, so preparations lacking a membrane fraction, such as cytosol-only lysate, can miss the protein | Use whole-cell or microsomal membrane lysates and include a membrane-solubilizing detergent in the lysis buffer |
| Band lower than expected | single-pass membrane proteins often migrate faster than their calculated mass on SDS-PAGE, and signal peptide cleavage further reduces mass below the 59.6 kDa precursor prediction | Confirm identity against the empirical 55 kDa band reported for UGT1A1 rather than the 59.6 kDa calculated precursor mass |
| Broad smear instead of sharp band | heterogeneous occupancy of the three N-glycosylation sites creates a mixture of glycoforms | Run a longer resolving gel or treat lysate with PNGase F to collapse glycoforms into a single deglycosylated band for comparison |
| Multiple bands | the two annotated splice isoforms can be co-expressed, or the antibody may cross-react with other closely related UGT1A family members | Verify the target band against a UGT1A1-positive control tissue such as liver and check the immunogen region against isoform and paralog sequences |
| Weak or no signal | UGT1A1 expression is largely restricted to liver and intestine, so cell lines or tissues with low expression give minimal signal | Include a known-positive liver tissue lysate as a control and increase loading or antibody concentration if needed |
Experiment evidence
Western blot images showing UGT1A1 band
A01865-1 · UGT1A1
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for UGT1A1 Western blot
🧪For positive controls for UGT1A1 in Western blot, you can use human liver tissue lysate or the HepG2 hepatocyte cell line, which are the classical sources of endogenous UGT1A1 protein.
Positive control: Liver tissue (HepG2 cells)
Negative control: ubiquitously expressed; use siRNA knockdown or KO line
Loading controls: Run GAPDH, β-actin, and a total-protein stain (stain-free gel, Ponceau S, or REVERT) alongside as loading controls.
⚠️Feasibility: As an ER membrane-anchored protein, UGT1A1 may require a microsomal/membrane-enriched fraction rather than whole-cell lysate for a strong signal, and since no HPA expression data are available here, a knockdown/KO negative control is advisable to confirm antibody specificity.
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 UGT1A1 Western Blot Tips
Deeper troubleshooting and optimisation questions for UGT1A1, answered from its protein features.
Why does UGT1A1 run at ~55 kDa instead of 59.6 kDa?
Cleavage of the 25-residue N-terminal signal peptide removes several kDa from the full-length calculated mass, and the single-pass transmembrane domain binds SDS less uniformly, causing anomalous migration. Together these explain the ~55 kDa apparent mass versus the 59.6 kDa predicted mass. Expect the exact band position to vary slightly with gel percentage, sample buffer, and transfer conditions.
Could isoform 2 appear as a separate band?
UGT1A1 has 2 annotated isoforms arising from alternative splicing. If your antibody epitope is retained in isoform 2, a second band at a different apparent mass may appear. Check which isoform your antibody targets before interpreting an extra band, and treat a consistent second band as a likely isoform rather than nonspecific binding.
Does induction change the UGT1A1 band intensity?
UGT1A1 is transcriptionally regulated in liver and intestinal tissue, with expression rising under conditions that activate hepatic drug-metabolizing pathways. Such treatments can increase total protein signal without shifting apparent molecular weight. Always compare induced samples to matched untreated controls so intensity changes reflect induction rather than loading variability.
How do the 3 glycosylation sites affect the band pattern?
UGT1A1 carries 3 predicted N-glycosylation sites, which can give a diffuse or slightly smeared band instead of one sharp line. Treating lysates with PNGase F before SDS-PAGE can collapse this heterogeneity into a single, sharper band closer to the deglycosylated core mass, improving confidence in size confirmation.
What blocking approach suits a glycosylated ER membrane protein?
Standard 5% non-fat milk or BSA in TBST works for UGT1A1; if background appears near the 55 kDa region, switch to BSA since milk glycoproteins can sometimes cross-react with glycoprotein targets. Because membrane extracts carry more residual lipid and detergent, use extended TBST washes before blocking to keep background low.
What transfer method to use for UGT1A1 Western blot?
As a 59.6 kDa single-pass ER membrane protein, use wet (tank) transfer with a methanol-containing buffer to efficiently elute the hydrophobic transmembrane region onto PVDF. Extend transfer time or reduce current for more complete transfer, since membrane-embedded proteins transfer less efficiently than soluble proteins of comparable size.
Should I check for dimer bands when quantifying UGT1A1?
UGT1A1 forms homodimers and heterodimers with other UGT1A family members. Although no disulfide bonds are annotated, incomplete denaturation can leave SDS-resistant oligomeric species above the monomer. Ensure thorough sample reduction and heating, and quantify only the ~55 kDa monomer band to avoid misrepresenting total signal.
Why might extra bands from other UGT1A enzymes appear?
UGT1A1 forms heterodimers with UGT1A3, UGT1A4, UGT1A6, UGT1A7, UGT1A8, UGT1A9, and UGT1A10, reflecting shared family sequence regions. Antibodies raised against conserved epitopes can cross-react with these paralogs, producing additional bands near the expected size. Validate specificity using UGT1A1-depleted lysate or an isoform-specific antibody.
Boster reagents
Best UGT1A1 Western Blot Antibodies
BosterBio's UGT1A1 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-UGT1A1 Antibody Picoband®
Cat # A01865-1
This UGT1A1 antibody panel currently lists a single Boster reagent (A01865-1) with a documented Western blot result, giving straightforward reagent selection for this target.
Which to pick: Only one anti-UGT1A1 antibody is catalogued: A01865-1, which includes an actual WB validation image (10% SDS-PAGE, 80V/120V). Use it as the default choice, since no alternative SKUs are listed for comparison.
Source: BosterBio UGT1A1 gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry P22309.
- Human Protein Atlas. UGT1A1 tissue expression.