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- Table of Contents
GEM / GTP-binding protein GEM · Western blot design guide
Design a Western Blot for GEM
Real validated GEM Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-GEM 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
GEM 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 | ~33.9 kDa | |
| Gel | 12–15% (standard starting point) | |
| Positive control | Adrenal gland (IHC candidate; verify WB) +4 more | |
| Negative control | Adipose tissue (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 | 1 isoform(s) |
Section 1
Real Curated GEM Western Blot Protocols
The A02200 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | Target-positive lysate and matched negative control (standard starting point) |
| Gel % | 12–15% (standard starting point) |
| Load | 20–30 µg total protein per lane; optimize for abundance (standard starting point) |
| Transfer | Standard semi-dry transfer; verify efficiency (standard starting point) |
| Membrane | 0.45 µm PVDF (standard starting point) |
| Blocking | 5% milk or 5% BSA in TBST (standard starting point) |
| Primary antibody | A02200; use the WB datasheet starting dilution (standard starting point) |
| Primary incubation | Overnight at 4 °C (standard starting point) |
| Secondary antibody | Species-matched HRP conjugate at validated dilution (standard starting point) |
| Secondary incubation | 1 h at room temperature (standard starting point) |
| Wash | 3 × 5 min in TBST (standard starting point) |
| Detection | ECL; bracket exposures to avoid saturation (standard starting point) |
Section 2
What Is the Expected GEM Western Blot Band Size?
GEM is predicted at 33.9 kDa; membrane association may affect recovery, but no distinct migration pattern is demonstrated.
| Band near 33.9 kDa | Consistent with GEM's predicted mass; confirm identity with antibody controls |
| Band at another position | Its identity and reason for differing migration are unestablished |
| Band enriched in a membrane fraction | Consistent with GEM's peripheral association with the cytoplasmic side of the cell membrane |
| Little or no band in a depleted lysate fraction | GEM may have partitioned with the membrane fraction |
💡Expected GEM appearanceUniProt predicts GEM at 33.9 kDa, but no empirical band size is supplied; assess any candidate band with antibody specificity and fractionation controls.
| UniProt predicted mass of 33.9 kDa | Provides the reference size for a GEM band |
| UniProt molecular weight of 33,949 Da | Expresses the same predicted mass in daltons |
| Predicted mass of the 296-residue GEM sequence | Does not establish an empirical migration position |
| UniProt predicted GEM mass | Does not establish a separate fragment or alternative isoform size |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | Peripheral membrane GEM may have been lost during preparation | Check the membrane fraction and extraction conditions |
| Band higher than expected | The supplied features do not establish why it migrates higher | Compare with a validated positive control and check antibody specificity |
| Band lower than expected | Its identity or cause is unestablished | Check antibody specificity and sample integrity |
| Multiple bands | No named isoforms are supplied to explain them | Use antibody specificity controls to identify the GEM band |
| Weak or no signal | Recovery of peripheral membrane GEM may be low | Compare whole lysate with a membrane-enriched fraction |
Experiment evidence
Western blot images showing GEM band
A02200 · GEM
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for GEM Western blot
🧪HPA-IHC candidate guidance (verify in WB): For positive controls for GEM in Western blot, you can use adrenal gland tissue, which shows high HPA expression.
Positive control: Adrenal gland (IHC candidate; verify WB)
Negative control: Adipose tissue (IHC candidate; verify WB)
Loading controls: Run GAPDH, β-actin, and a total-protein stain such as Ponceau alongside the samples.
⚠️Feasibility: GEM is membrane-associated, so membrane-enriched lysate may help if whole-cell signal is weak.
HPA tissue expression evidence for GEM
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 → |
| Bronchus | respiratory epithelial cells | High | Protein (IHC) | HPA → |
| Cerebellum | Purkinje cells | High | Protein (IHC) | HPA → |
| Cervix | glandular cells | High | Protein (IHC) | HPA → |
| Colon | glandular cells | High | Protein (IHC) | HPA → |
Lower expression tissues · IHC evidence, not confirmed WB-negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| Adipose tissue | adipocytes | Not detected | Protein (IHC) | HPA → |
| Ovary | ovarian stroma cells | Not detected | Protein (IHC) | HPA → |
| Prostate | glandular cells | Not detected | Protein (IHC) | HPA → |
| Seminal vesicle | glandular cells | Not detected | Protein (IHC) | HPA → |
| Epididymis | glandular cells | Low | Protein (IHC) | HPA → |
Section 3
Advanced GEM Western Blot Tips
Deeper troubleshooting and optimisation questions for GEM, answered from its protein features.
Where should the main GEM band be expected?
Band shift · GEM has a predicted mass of 33.9 kDa. No observed Western blot band position is supplied, so use 33.9 kDa as a reference rather than an established apparent mass.
Does GEM have documented isoforms that could produce multiple bands?
Isoforms · The supplied record lists one isoform and no alternative sequence. It does not support assigning multiple bands to GEM isoforms.
Could phosphorylation account for a GEM band shift?
PTM · GEM is labeled a phosphoprotein, but the supplied record lists no modified residue coordinates. Phosphorylation cannot be assigned to a particular band from these features, and its presence alone does not establish a visible shift.
The supplied features list no signal peptide, propeptide, or glycosylation sites. They provide no basis to assign an unexpected band to those forms of GEM; its identity needs experimental verification.
The supplied features list no signal peptide, propeptide, or glycosylation sites. They provide no basis to assign an unexpected band to those forms of GEM; its identity needs experimental verification.
Does this guide establish induction of GEM?
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.
How should transfer be checked for GEM?
Transfer · Standard workflow guidance: verify transfer efficiency for the intended target size before interpreting a weak signal. Use total-protein assessment and optimize transfer for the membrane, gel and apparatus; the labelled catalog values take precedence.
How should blocking be optimized?
Blocking · Standard workflow guidance: follow the A02200 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 GEM samples be prepared for comparable quantitation?
Quantitation · GEM is listed as a peripheral membrane protein on the cytoplasmic side. Use the same sample fraction and preparation across lanes so differences in membrane recovery do not confound comparisons.
Do GEM binding partners explain unexpected bands?
Interpretation · GEM binds ROCK1 and interacts with calmodulin in a Ca(2+)-dependent manner. Those interactions alone do not identify an unexpected band or establish that a complex survives Western blot preparation.
Boster reagents
GEM 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-GTP-binding protein GEM GEM Antibody
Cat # A02200
The catalog reports one anti-GEM antibody, A02200, with stated human and mouse reactivity. Its WB image shows DU145 cell lysates probed at 1:1000 after overnight incubation at 4°C. No publication evidence or additional sample validation is supplied.
Which to pick: A02200 is the only listed option and has a WB image from DU145 cells. Its listed reactivity is human and mouse; the supplied image documents the DU145 context only.
Source: BosterBio GEM gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry P55040.
- Human Protein Atlas. GEM tissue expression.
- PMC3937318 — target-verified WB comparison