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- Table of Contents
CIRBP / Cold-inducible RNA-binding protein · Western blot design guide
Design a Western Blot for CIRBP
Source-linked CIRBP Western blot protocol options, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-CIRBP 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
CIRBP 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 | ~18.6 kDa | |
| Observed band | ~19 kDa | |
| Gel | 12% (catalog M04103) | |
| Negative control | Suggested KO / knockdown lysate |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | Phosphorylated | |
| Caveat | Phosphorylation-state controls | |
| Gene-set association | MSigDB C7 membership | |
| Isoform | 3 isoform(s) |
Section 1
Source-Linked CIRBP Western Blot Protocol Options
The M04103 protocol combines labelled catalog values with standard starting conditions. Published comparisons retain their own sample, reagent and detection scope.
| Sample / lysate | human HepG2, human RT4, human U251, human HEL (catalog M04103) |
| Gel % | 12% (catalog M04103) |
| Load | 30 ug; reducing conditions (catalog M04103) |
| Transfer | a nitrocellulose membrane at 150 mA for 50-90 minutes (catalog M04103) |
| Membrane | nitrocellulose membrane (catalog M04103) |
| Blocking | 5% non-fat milk/TBS for 1.5 hour at RT (catalog M04103) |
| Primary antibody | M04103 · 1: 500 (catalog M04103) |
| Primary incubation | overnight at 4°C (catalog M04103) |
| Secondary antibody | goat anti-rabbit IgG-HRP, 1:5000 (catalog M04103) |
| Secondary incubation | 1.5 hour at RT (catalog M04103) |
| Wash | TBS-0.1%Tween 3 times with 5 minutes each (catalog M04103) |
| Detection | ECL (catalog M04103) |
Section 2
What Is the Expected CIRBP Western Blot Band Size?
CIRBP is predicted at 18.6 kDa and observed at ~19 kDa; the cause of the small difference is not established.
| Band at ~19 kDa in whole-cell lysate | Matches the empirical CIRBP band; confirm identity with appropriate controls. |
| Several bands near ~19 kDa | Isoforms 1, 2 and 3 are reported, but their migration differences are unknown. |
| Band in a nuclear fraction | Consistent with CIRBP localization in the nucleoplasm. |
| Band in a cytoplasmic fraction after stress | Consistent with reported movement of CIRBP from nucleus to cytoplasm. |
💡Expected CIRBP appearanceCIRBP has a predicted mass of 18.6 kDa and an observed band at ~19 kDa in reducing whole-cell blots; confirm band identity with an appropriate specificity control.
| Predicted CIRBP mass | 18.6 kDa is the sequence-based reference; the observed band is ~19 kDa. |
| Isoform 1 | Its size relative to the other isoforms is not supplied. |
| Isoform 2 | Its size relative to the other isoforms is not supplied. |
| Isoform 3 | Its size relative to the other isoforms is not supplied. |
| Situation | Likely cause | Next action |
|---|---|---|
| Multiple bands | Alternative isoforms are reported, but distinct band positions are unverified. | Check antibody specificity with CIRBP depletion and compare the band pattern. |
| Band higher than expected | The cause of slower migration is not established by the supplied evidence. | Compare with the ~19 kDa control band and verify identity by CIRBP depletion. |
| Band lower than expected | An isoform or protein breakdown may contribute; no fragment mass is supplied. | Use fresh, protected lysate and verify the band by CIRBP depletion. |
| Weak or no signal | CIRBP distribution between nucleus and cytoplasm can change after stress. | Check whole-cell and matched nuclear and cytoplasmic fractions. |
| Fragments below expected size | Protein breakdown is possible, but no CIRBP cleavage product is specified. | Prepare fresh lysate with protease inhibitors and check whether fragments diminish. |
Experiment evidence
Western blot images showing CIRBP band
M04103 · CIRBP
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for CIRBP Western blot
🧪For positive controls for CIRBP in Western blot, you can use a tissue or cell sample after confirming CIRBP expression; the supplied HPA data identify no positive sample.
Positive control: No high/medium HPA tissue identified
Negative control: Suggested KO / knockdown lysate
Loading controls: Run GAPDH, β-actin, and a total-protein stain such as Ponceau alongside the samples.
⚠️Feasibility: The supplied HPA data identify no tissue controls, so a CIRBP knockdown or KO line is the more practical negative control.
HPA tissue expression evidence for CIRBP
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 |
|---|---|---|---|---|
| No high/medium HPA tissues identified in the supplied evidence. | ||||
Lower expression tissues · IHC evidence, not confirmed WB-negative controls
| Tissue | Cell type | Level | Evidence | Source |
|---|---|---|---|---|
| No lower-expression tissue rows available in the supplied evidence. | ||||
Section 3
Advanced CIRBP Western Blot Tips
Deeper troubleshooting and optimisation questions for CIRBP, answered from its protein features.
How should CIRBP 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 CIRBP isoforms produce different bands?
Isoforms · UniProt lists three isoforms. Isoform 2 lacks canonical residues 83–116; isoform 3 replaces residues 1–69. Both have an alternative sequence beginning at position 167. These changes could affect migration, but they do not establish where any isoform will appear on a blot.
Which CIRBP phosphorylation sites should I consider?
PTM · UniProt lists phosphoserine at positions 130, 138, 146, 156, 159, and 163, using its canonical sequence numbering. These sites may matter when comparing samples, but their presence alone does not demonstrate a visible band shift.
Does this guide establish induction of CIRBP?
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 CIRBP Western blot?
Transfer · CIRBP is predicted at 18.6 kDa and observed near 19 kDa. Choose transfer conditions suitable for a protein of this size, then check membrane staining and the post-transfer gel to assess transfer and retention.
How should blocking be optimized?
Blocking · Standard workflow guidance: follow the M04103 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 I quantify CIRBP across stressed samples?
Quantitation · CIRBP occurs in the nucleus and cytoplasm and can move into cytoplasmic stress granules during stress. Compare equivalent sample fractions and normalize within each fraction; a change in one fraction need not reflect a change in total CIRBP.
Why is the CIRBP band near 19 kDa?
Interpretation · The observed band near 19 kDa is close to the predicted 18.6 kDa mass of canonical CIRBP. The listed features alone do not establish why apparent and predicted masses differ.
UniProt reports that CIRBP moves from the nucleus to the cytoplasm after UV exposure. If comparing nuclear and cytoplasmic fractions, assess both fractions before interpreting a change in one as a change in total CIRBP.
Compare them with the ~19 kDa observed band and consider the three listed isoforms and six phosphorylation sites as possibilities. The features do not assign an identity to an extra band or show that phosphorylation causes a resolvable shift; confirm band identity experimentally.
UniProt reports that CIRBP moves from the nucleus to the cytoplasm after UV exposure. If comparing nuclear and cytoplasmic fractions, assess both fractions before interpreting a change in one as a change in total CIRBP.
Compare them with the ~19 kDa observed band and consider the three listed isoforms and six phosphorylation sites as possibilities. The features do not assign an identity to an extra band or show that phosphorylation causes a resolvable shift; confirm band identity experimentally.
Boster reagents
CIRBP 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-CIRBP Rabbit Monoclonal Antibody
Cat # M04103
M04103 is a rabbit monoclonal anti-CIRBP antibody listed for human and mouse. Its Western blot image shows an approximately 19 kDa band in four human cell lysates, matching the expected size. The supplied evidence does not show a mouse blot.
Which to pick: M04103 is the only listed option. Its Western blot image uses human HepG2, RT4, U251, and HEL whole cell lysates; mouse reactivity is listed, but no mouse Western blot image is supplied.
Source: BosterBio CIRBP gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry Q14011.
- Human Protein Atlas. CIRBP tissue expression.
- PMC5436571 — target-verified WB comparison
- PMC8417580 — target-verified WB comparison
- PMC13367901 — target-verified WB comparison