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- Table of Contents
SOS1 / Son of sevenless homolog 1 · Western blot design guide
Design a Western Blot for SOS1
Real validated SOS1 Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-SOS1 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
SOS1 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 | ~152.5 kDa | |
| Observed band | ~170 kDa | |
| Gel | 5–20% (catalog A00837-1) | |
| Positive control | Cerebral cortex (IHC candidate; verify WB) +4 more | |
| Negative control | Caudate (IHC candidate; verify WB) |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | Phosphorylated | |
| Caveat | Phosphorylation-state controls | |
| Gene-set association | MSigDB Hallmark membership | |
| Isoform | 2 isoform(s) |
Section 1
Real Curated SOS1 Western Blot Protocols
The A00837-1 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | human K562, human THP-1, human HEL (catalog A00837-1) |
| Gel % | 5–20% (catalog A00837-1) |
| Load | 30 ug; reducing conditions (catalog A00837-1) |
| Transfer | a nitrocellulose membrane at 150 mA for 50-90 minutes (catalog A00837-1) |
| Membrane | nitrocellulose membrane (catalog A00837-1) |
| Blocking | 5% non-fat milk/TBS for 1.5 hour at RT (catalog A00837-1) |
| Primary antibody | A00837-1 · 0.5 μg/mL (catalog A00837-1) |
| Primary incubation | overnight at 4°C (catalog A00837-1) |
| Secondary antibody | goat anti-rabbit IgG-HRP, 1:5000 (catalog A00837-1) |
| Secondary incubation | 1.5 hour at RT (catalog A00837-1) |
| Wash | TBS-0.1%Tween 3 times with 5 minutes each (catalog A00837-1) |
| Detection | ECL (catalog A00837-1) |
Section 2
What Is the Expected SOS1 Western Blot Band Size?
SOS1 is predicted at 152.5 kDa and observed near 170 kDa; the cause of that difference is not established.
| Band near 170 kDa | matches the reported SOS1 band; confirm identity with controls |
| Band near 152.5 kDa | near the predicted sequence mass; identity requires confirmation |
| Two bands at different positions | could reflect SOS1 isoforms 1 and 2, but their migration is unestablished |
| Minor band beside the main band | could reflect a different phosphorylation state; a visible shift is unproven |
💡Expected SOS1 appearanceSOS1 has a predicted mass of 152.5 kDa, while antibody QC reports a band near 170 kDa; the cause of the difference is unestablished, so confirm identity with appropriate controls.
| Predicted sequence mass | 152.5 kDa by sequence, versus the reported band near 170 kDa |
| Isoform 1 | annotated splice isoform with no supplied individual mass or migration |
| Isoform 2 | annotated splice isoform with no supplied individual mass or migration |
| Alternative splicing of isoforms 1 and 2 | may alter size, but distinct bands are not established |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | SOS1 signal is undetected | check loading, transfer, and a positive control lysate |
| Band higher than expected | the reported SOS1 band is near 170 kDa, above its predicted 152.5 kDa | compare with the reported band and confirm identity using an independent antibody |
| Band lower than expected | band identity or isoform contribution is uncertain | check the molecular weight marker and confirm with an independent antibody |
| Multiple bands | isoforms 1 and 2 or different phosphorylation states are possible, but their migration is unestablished | compare bands across controls and verify SOS1 identity |
| Weak or no signal | SOS1 signal may be below detection | check loading and transfer, then test a positive control lysate |
Experiment evidence
Western blot images showing SOS1 band
A00837-1 · SOS1
M00837 · SOS1
M00837 · SOS1
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for SOS1 Western blot
🧪HPA-IHC candidate guidance (verify in WB): For positive controls for SOS1 in Western blot, you can use cerebral cortex lysate, which HPA rates High.
Positive control: Cerebral cortex (IHC candidate; verify WB)
Negative control: Caudate (IHC candidate; verify WB)
Loading controls: Run GAPDH, β-actin, and a total-protein stain alongside the samples.
⚠️Feasibility: HPA lists both High and Not detected tissues, making tissue controls feasible.
HPA tissue expression evidence for SOS1
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 |
|---|---|---|---|---|
| Cerebral cortex | neuronal cells | High | Protein (IHC) | HPA → |
| Hippocampus | neuronal cells | High | Protein (IHC) | HPA → |
| Ovary | follicle cells | High | Protein (IHC) | HPA → |
| Placenta | trophoblastic cells | High | Protein (IHC) | HPA → |
| Testis | cells in seminiferous ducts | High | Protein (IHC) | HPA → |
Lower expression tissues · IHC evidence, not confirmed WB-negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Caudate | glial cells | Not detected | Protein (IHC) | HPA → |
| Cervix | glandular cells | Not detected | Protein (IHC) | HPA → |
| Oral mucosa | squamous epithelial cells | Not detected | Protein (IHC) | HPA → |
| Prostate | glandular cells | Not detected | Protein (IHC) | HPA → |
| Skeletal muscle | myocytes | Not detected | Protein (IHC) | HPA → |
Section 3
Advanced SOS1 Western Blot Tips
Deeper troubleshooting and optimisation questions for SOS1, answered from its protein features.
How should SOS1 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 the two SOS1 isoforms produce different bands?
Isoforms · Yes. Isoform 2 lacks canonical residues 1–57 and 372–1333 and replaces residues 359–371. It could therefore migrate differently from full-length isoform 1. Check whether the antibody recognizes a region retained in the isoform you want to detect.
Which phosphorylation sites matter when interpreting SOS1 bands?
PTM · UniProt lists phosphoserines at positions 1078, 1082, 1134, 1161, 1178, 1210, 1229, and 1275; RPS6KA3 is specified for 1134 and 1161. These are UniProt canonical-sequence coordinates and may differ from antibody or paper numbering. Their presence does not establish a visible band shift.
Match the antibody’s stated site to the UniProt canonical sequence. Listed phosphoserines are 1078, 1082, 1134, 1161, 1178, 1210, 1229, and 1275; RPS6KA3 is specified for 1134 and 1161. Isoform 2 lacks residues 372–1333, including these sites.
Match the antibody’s stated site to the UniProt canonical sequence. Listed phosphoserines are 1078, 1082, 1134, 1161, 1178, 1210, 1229, and 1275; RPS6KA3 is specified for 1134 and 1161. Isoform 2 lacks residues 372–1333, including these sites.
Does this guide establish induction of SOS1?
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 SOS1 Western blot?
Transfer · SOS1 isoform 1 is predicted at 152.5 kDa. Choose and verify transfer conditions that retain and transfer a protein of this size, using a high-molecular-weight marker to assess transfer at the target position.
How should blocking be optimized?
Blocking · Standard workflow guidance: follow the A00837-1 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 SOS1 bands be quantified?
Quantitation · Quantify a consistently identified SOS1 band within the assay’s linear signal range. Because isoform 2 has a large sequence deletion, establish which isoform the antibody detects before combining signals from different bands.
Why might SOS1 appear near 170 kDa instead of 152.5 kDa?
Interpretation · SOS1 has a predicted mass of 152.5 kDa, while the supplied observed band is approximately 170 kDa. The listed phosphorylation sites alone do not establish why it migrates there. Identify the band with a validated SOS1 antibody and an appropriate control.
Consider isoform 2: it lacks residues 1–57 and 372–1333 of the canonical sequence and replaces residues 359–371. A lower band is not identified by size alone. Confirm that the antibody recognizes a retained region and use a suitable specificity control.
Consider isoform 2: it lacks residues 1–57 and 372–1333 of the canonical sequence and replaces residues 359–371. A lower band is not identified by size alone. Confirm that the antibody recognizes a retained region and use a suitable specificity control.
Boster reagents
SOS1 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-SOS1 Antibody Picoband®
Cat # A00837-1
Real WB data
Anti-SOS1 Rabbit Monoclonal Antibody
Cat # M00837
The catalog reports two anti-SOS1 antibodies with Western blot images using human cell, rat brain and cell, and mouse brain and cell lysates. Both captions report a band near 170 kDa, above the expected 152 kDa; the supplied evidence does not establish band identity independently.
Which to pick: Both A00837-1 and M00837 list human, mouse and rat reactivity and have WB images. Choose by the closest documented sample: A00837-1 includes K562, THP-1 and NIH/3T3; M00837 includes HepG2, SH-SY5Y and Neuro-2a. Both include HEL, rat brain, C6 and mouse brain.
Source: BosterBio SOS1 gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry Q07889.
- Human Protein Atlas. SOS1 tissue expression.
- PMC6000274 — target-verified WB comparison
- PMC11694061 — target-verified WB comparison
- PMC6328564 — target-verified WB comparison