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- Table of Contents
TOMM40 / Mitochondrial import receptor subunit TOM40 homolog · Western blot design guide
Design a Western Blot for TOMM40
Source-linked TOMM40 Western blot protocol options, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-TOMM40 WB antibodies. Everything you need to plan the experiment before you commit precious samples.
Evidence assembled September 2026 · For research use; verify linked source records and product datasheet before use
TOMM40 Western Blot Experimental Design Guide
Expected bands, source-linked protocol options, controls and antibodies — the at-a-glance facts below, then the full design guide.
Must know before running
| Expected band | ~37.9 kDa | |
| Observed band | ~38 kDa | |
| Gel | 5–20% (catalog A03166-2) | |
| Positive control | Adrenal gland (IHC candidate; verify WB) +4 more | |
| Negative control | Soft tissue (IHC candidate; verify WB) |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | — | |
| Caveat | — | |
| Gene-set association | MSigDB Hallmark membership | |
| Isoform | 2 isoform(s) |
Section 1
Source-Linked TOMM40 Western Blot Protocol Options
The A03166-2 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | human Hela, human 293T, human MCF-7, human HepG2 (catalog A03166-2) |
| Gel % | 5–20% (catalog A03166-2) |
| Load | 30 ug; reducing conditions (catalog A03166-2) |
| Transfer | a nitrocellulose membrane at 150 mA for 50-90 minutes (catalog A03166-2) |
| Membrane | nitrocellulose membrane (catalog A03166-2) |
| Blocking | 5% non-fat milk/TBS for 1.5 hour at RT (catalog A03166-2) |
| Primary antibody | A03166-2 · 0.5 μg/mL (catalog A03166-2) |
| Primary incubation | overnight at 4°C (catalog A03166-2) |
| Secondary antibody | goat anti-rabbit IgG-HRP, 1:5000 (catalog A03166-2) |
| Secondary incubation | 1.5 hour at RT (catalog A03166-2) |
| Wash | TBS-0.1%Tween 3 times with 5 minutes each (catalog A03166-2) |
| Detection | ECL (catalog A03166-2) |
Section 2
What Is the Expected TOMM40 Western Blot Band Size?
TOMM40 is predicted at 37.9 kDa and observed at ~38 kDa; the small difference has no established cause in the supplied evidence.
| Band at ~38 kDa | Matches the observed TOMM40 band and its 37.9 kDa predicted mass. |
| Single sharp band near 38 kDa | Consistent with the reported TOMM40 band; confirm identity with ordinary controls. |
| Additional bands at different sizes | Isoforms 1 and 2 are documented, but distinct band positions are unverified. |
| Weak band in whole-cell lysate | Outer mitochondrial membrane localization may make recovery sensitive to sample preparation. |
💡Expected TOMM40 appearanceTOMM40 has a predicted mass of 37.9 kDa and an observed band at ~38 kDa in reducing whole-cell lysates; confirm band identity with an independent antibody or TOMM40 depletion.
| UniProt predicted mass | Places TOMM40 at 37.9 kDa, close to the observed ~38 kDa band. |
| Full-length 361-residue sequence | Provides the basis for the predicted 37.9 kDa mass. |
| Splice isoform 1 | Its apparent size relative to isoform 2 is not supplied. |
| Splice isoform 2 | Its apparent size relative to isoform 1 is not supplied. |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | TOMM40 is an outer mitochondrial membrane protein, so extraction may be inadequate. | Check membrane extraction and compare with a mitochondria-enriched fraction. |
| Band higher than expected | The supplied features do not establish a higher migrating TOMM40 form. | Check denaturation and confirm identity with TOMM40 depletion or an independent antibody. |
| Band lower than expected | An isoform may differ in size, but its mass is not supplied. | Confirm identity with TOMM40 depletion or an independent antibody. |
| Multiple bands | Isoforms 1 and 2 exist, but distinct bands are not established. | Check which bands respond to TOMM40 depletion. |
| Weak or no signal | Recovery of this outer mitochondrial membrane protein may be low. | Check membrane protein recovery and compare with a mitochondria-enriched fraction. |
Experiment evidence
Western blot images showing TOMM40 band
A03166-2 · TOMM40
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for TOMM40 Western blot
🧪HPA-IHC candidate guidance (verify in WB): For positive controls for TOMM40 in Western blot, you can use adrenal gland lysate, which HPA scores High.
Positive control: Adrenal gland (IHC candidate; verify WB)
Negative control: Soft tissue (IHC candidate; verify WB)
Loading controls: Run GAPDH, β-actin, and a total-protein stain alongside the samples.
⚠️Feasibility: HPA lists soft tissue as not detected, so it is a candidate negative control, but confirm the result in your lysate.
HPA tissue expression evidence for TOMM40
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.
Higher expression tissues · candidate positive controls from IHC
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adrenal gland | glandular cells | High | Protein (IHC) | HPA → |
| Appendix | glandular cells | High | Protein (IHC) | HPA → |
| Colon | glandular cells | High | Protein (IHC) | HPA → |
| Esophagus | squamous epithelial cells | High | Protein (IHC) | HPA → |
| Parathyroid gland | glandular cells | High | Protein (IHC) | HPA → |
Lower expression tissues · IHC evidence, not confirmed WB-negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Soft tissue | chondrocytes | Not detected | Protein (IHC) | HPA → |
| Adipose tissue | adipocytes | Low | Protein (IHC) | HPA → |
| Lung | macrophages | Low | Protein (IHC) | HPA → |
| Skeletal muscle | myocytes | Low | Protein (IHC) | HPA → |
| Smooth muscle | smooth muscle cells | Low | Protein (IHC) | HPA → |
Section 3
Advanced TOMM40 Western Blot Tips
Deeper troubleshooting and optimisation questions for TOMM40, answered from its protein features.
How should TOMM40 band migration be interpreted?
Band shift · Use the separately labelled calculated mass and catalog-observed evidence above. A sequence annotation does not establish an observed migration shift. Verify target identity with orthogonal controls.
Could TOMM40 isoforms produce different bands?
Isoforms · Yes. Isoform 2 replaces residues 317–329 and lacks residues 330–361, using isoform 1 coordinates. It may migrate differently, but these sequence differences alone do not establish where a second band will appear.
Do listed modifications explain a shifted TOMM40 band?
PTM · No modified residues or glycosylation sites are listed. The supplied features therefore provide no specific modification to assign to a shifted band; they also do not rule out unlisted modifications.
Does this guide establish induction of TOMM40?
Induction · No general induction response is established by this guide. A pathway or gene-set association is not evidence of induction in a particular specimen. Verify the relevant treatment and control in a target-specific experiment.
What transfer method to use for TOMM40 Western blot?
Transfer · TOMM40 is a multi-pass outer mitochondrial membrane protein. The supplied features do not prescribe a transfer method. Check transfer efficiency around 38 kDa and optimize the method against the retained protein and detected signal.
How should blocking be optimized?
Blocking · Standard workflow guidance: follow the A03166-2 datasheet where specified. Otherwise compare 5% milk or 5% BSA in TBST; for a phospho-specific assay start with BSA. Optimize background and specific signal with matched controls.
How should TOMM40 bands be quantified?
Quantitation · Quantify the approximately 38 kDa band consistently across samples, using exposures within the assay's linear range. If another band is present, assess it separately before combining signals: two isoforms are listed, but their migration has not been established here.
Should TOMM40 migrate away from its predicted mass?
Interpretation · The predicted mass is 37.9 kDa, and the reported band is approximately 38 kDa. These agree closely. The supplied features do not establish a shift.
First compare them with the approximately 38 kDa band and consider isoform 2's altered C-terminal sequence. TOMM40 also resides in a membrane protein complex, so an upper band could warrant checking sample denaturation. Neither feature identifies an unexpected band on its own.
First compare them with the approximately 38 kDa band and consider isoform 2's altered C-terminal sequence. TOMM40 also resides in a membrane protein complex, so an upper band could warrant checking sample denaturation. Neither feature identifies an unexpected band on its own.
Boster reagents
TOMM40 Western Blot Antibodies
Catalog antibodies with Western blot application and product-specific WB images. Evaluate suitability with the reported sample, controls and experimental conditions.
Real WB data
Anti-TOMM40 Antibody Picoband®
Cat # A03166-2
The catalog reports one anti-TOMM40 antibody, A03166-2, with human reactivity. Its Western blot image reports a band near the expected 38 kDa in HeLa, 293T, MCF-7, and HepG2 whole cell lysates. No publication evidence or independent validation is supplied.
Which to pick: A03166-2 is the only listed option. It has a Western blot image using human whole cell lysates, making it the documented choice for those sample contexts. Reactivity outside human samples is not listed.
Source: BosterBio TOMM40 gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry O96008.
- Human Protein Atlas. TOMM40 tissue expression.
- PMC13380028 — target-verified WB comparison
- PMC12767443 — target-verified WB comparison
- PMC13469937 — target-verified WB comparison