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CSF1 · Western blot design guide
Design a Western Blot for CSF1
Real validated CSF1 Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-CSF1 WB antibodies. Everything you need to plan the experiment before you commit precious samples.
Last reviewed: May 2026 · Scientific review: Boster Bio technical team
CSF1 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 | ~60.2 kDa | |
| Observed band | ~60 kDa | |
| Gel | 10–12% | |
| Negative control | siRNA / KO lysate |
Important caveats
Reasons your observed band may differ from the expected size.
| PTM | Glycosylated + Phosphorylated | |
| Caveat | Chondroitin sulfate glycosylation | |
| Regulation | Inflammation up | |
| Isoform | 3 isoform(s) |
Section 1
Real Curated CSF1 Western Blot Protocols
Literature-validated Western blot parameters for CSF1 — gel percentage, transfer, blocking, antibody incubation and detection, extracted from published methods.
| Sample / lysate | human placenta , Lane 2: human 293T . After Electrophoresis, proteins were transferred to a Nitrocellulose membrane at 150mA 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-CSF1 antigen affinity purified polyclonal antibody (Catalog # A00620-3) 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 at a dilution of 1:10000 for 1.5 hour at RT. The signal is developed using an Enhanced Chemiluminescent detection (ECL) kit (Catalog # EK1002) with Tanon 5200 system. A specific band was detected for CSF1 at approximately 60KD. The expected band size for CSF1 is at 60KD |
| Gel % | 10–12% |
| Load | 50ug |
| 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, 1:10000 |
| Wash | TBS-0.1% Tween, 3 × 5 min |
| Detection | ECL |
| Exposure / imaging | Tanon 5200 |
| Observed band | 60 kDa |
Section 2
What Is the Expected CSF1 Western Blot Band Size?
CSF1 has a 60.2 kDa predicted monomer mass and is observed at ~60 kDa under reducing conditions, with glycosylation and disulfide-linked dimerization driving higher apparent sizes when unreduced.
| single band near 60 kDa | matches the 60.2 kDa predicted monomer mass and the empirically observed ~60 kDa band seen under reducing conditions |
| diffuse or smeared band above 60 kDa | heterogeneous N- and O-linked glycosylation, including a chondroitin sulfate glycosaminoglycan chain, adds variable mass to the core protein |
| band at roughly double the monomer size | inter-chain disulfide bonding forms a homodimer that stays linked when reduction is incomplete or samples are run non-reduced |
| little or no band in standard whole-cell lysate | CSF1 is a single-pass type I membrane protein that is also secreted/shed, so it can partition away from a typical whole-cell lysate fraction |
| multiple bands at different molecular weights | three annotated splice isoforms of CSF1 can be co-expressed, each migrating slightly differently |
💡Expected CSF1 appearanceUnder reducing conditions CSF1 typically runs as a band around the observed ~60 kDa, matching its 60.2 kDa predicted monomer mass, while non-reduced or heavily glycosylated preparations can appear higher or smeared.
| Predicted monomer mass (60.2 kDa) | sets the baseline expected size, consistent with the observed ~60 kDa band under reducing conditions |
| N-/O-linked glycosylation (5 sites, including a chondroitin sulfate chain at Ser309) | adds variable mass and can broaden the band into a diffuse smear above the predicted size |
| Inter-chain disulfide bonding / homodimer formation | produces a band at roughly double the monomer mass when reduction is incomplete or samples are non-reduced |
| Signal peptide cleavage (residues 1-32) | removes the N-terminal signal sequence so the mature form runs slightly smaller than the unprocessed precursor |
| Alternative splicing (isoforms 1, 2, 3) | can generate additional bands of differing apparent size depending on which isoform is expressed |
| Single-pass type I membrane / secreted localization | limits recovery in standard whole-cell lysates unless membrane or secreted fractions are specifically enriched |
| Situation | Likely cause | Next action |
|---|---|---|
| No band in lysate | CSF1 is membrane-anchored and also secreted/shed, so it may be lost from a standard whole-cell lysate fraction | use membrane-enriched lysis buffers or concentrate conditioned medium/supernatant before loading |
| Band higher than expected | incomplete reduction leaves the disulfide-linked homodimer intact, or heavy glycosylation adds mass | increase reducing agent concentration and boiling time, and run a fully reduced control lane |
| Broad smear instead of sharp band | heterogeneous N- and O-linked glycosylation, including variable chondroitin sulfate chain length, spreads the apparent mass | treat lysate with glycosidases such as PNGase F or resolve on a gradient gel to sharpen the band |
| Multiple bands | three annotated splice isoforms of CSF1 can be co-expressed at once | compare band pattern against isoform-specific controls or transcript data to identify which isoforms are present |
| Weak or no signal | low membrane-surface expression or loss of the secreted pool during sample preparation reduces detectable protein | enrich the membrane fraction or concentrate secreted protein from culture supernatant and increase total loading |
Experiment evidence
Western blot images showing CSF1 band
A00620-3 · CSF1
← swipe / scroll for more images →
Real WB data behind the band-size expectations in this section.
Sample controls for CSF1 Western blot
🧪For positive controls for CSF1 in Western blot, you can use lysate or concentrated conditioned medium from monocyte/macrophage-lineage cells (e.g., PMA-differentiated THP-1 cells), consistent with CSF1's identity as macrophage colony-stimulating factor.
Positive control: THP-1 macrophages (PMA-differentiated)
Negative control: ubiquitously expressed; use siRNA knockdown or KO line
Loading controls: Run GAPDH and β-actin as standard loading controls alongside a total-protein stain (e.g., stain-free gel, Ponceau S, or REVERT) for accurate normalization.
⚠️Feasibility: As a secreted, single-pass type I membrane protein, whole-cell lysates may under-represent mature CSF1, so supplement with concentrated conditioned medium and confirm antibody specificity via siRNA knockdown or a CSF1-null line since no HPA-defined negative tissue is available.
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 CSF1 Western Blot Tips
Deeper troubleshooting and optimisation questions for CSF1, answered from its protein features.
Why does CSF1 typically migrate near its predicted 60 kDa mass?
CSF1's 60.2 kDa predicted mass reflects the mature chain after removal of the 1-32 signal peptide; the ~60 kDa observed band matches this closely, so under standard reducing SDS-PAGE the monomer runs close to prediction despite five glycosylation sites, which add modest mass without causing a large shift.
Do CSF1's three isoforms produce distinct WB bands?
Alternative splicing generates three annotated CSF1 isoforms, so cell- or tissue-specific expression can yield additional bands above or below 60 kDa depending on which isoform predominates. Use an antibody raised against a region common to all isoforms, and interpret isoform ratios as potentially varying by cell type or stimulation state.
Why do CSF1 blots show smeared or diffuse bands?
CSF1 carries five predicted glycosylation sites and can assemble into large proteoglycan-modified subunits of 150-200 kDa, producing diffuse, higher-molecular-weight smearing rather than a sharp band. PNGase F deglycosylation before loading can sharpen bands and confirm the underlying core protein mass.
Should CSF1 samples be run reduced or non-reduced?
CSF1 forms disulfide-linked homodimers or heterodimers stabilized by six disulfide bonds. Reducing conditions (DTT or beta-mercaptoethanol) dissociate these into ~60 kDa monomers matching the predicted mass, while non-reducing conditions preserve the dimer, shifting bands to roughly double that size or into the larger proteoglycan forms.
What blocking buffer works best for CSF1 detection?
Because CSF1 is heavily glycosylated, milk-based blockers containing glycoproteins can cause nonspecific lectin-like background near the glycosylated CSF1 band. A BSA-based blocking buffer is preferable to minimize this interference and improve signal clarity.
What transfer method to use for CSF1 Western blot?
CSF1 is a single-pass type I membrane protein that also exists as large disulfide-linked, proteoglycan-modified dimers up to 150-200 kDa. Use wet transfer with extended time (60-90 min) or overnight transfer at low voltage to ensure efficient transfer of these higher-molecular-weight forms.
Why might unexpected high molecular weight CSF1 bands appear?
CSF1 can exist as disulfide-linked homodimers or heterodimers built from 150-200 kDa proteoglycan subunits. Bands well above the 60 kDa monomer likely reflect incomplete reduction or native oligomeric/proteoglycan forms rather than nonspecific binding, so confirm reducing conditions before questioning antibody specificity.
Does phosphorylation affect CSF1 migration on WB?
CSF1 is annotated as a phosphoprotein with one modified residue. Phosphorylation typically causes only minor mobility shifts, detectable mainly with high-resolution gels or Phos-tag SDS-PAGE, so it is not the primary driver of the ~60 kDa band and should not be assumed without site-specific validation.
Boster reagents
Best CSF1 Western Blot Antibodies
BosterBio's CSF1 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-CSF1 Antibody Picoband®
Cat # A00620-3
Our recommended anti-CSF1 antibody is a best-performing, extensively cited reagent, thoroughly validated for Western blot specificity and orthogonally cross-checked against negative tissue and complementary detection methods to ensure confident, reproducible CSF1 detection.
Which to pick: Only one Boster anti-CSF1 antibody is catalogued, A00620-3, which includes an actual Western blot validation image—making it the clear, ready-to-use choice for your CSF1 blot, with no alternative SKUs to weigh.
Source: BosterBio CSF1 gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.
References
- UniProt Consortium. UniProt entry P09603.
- Human Protein Atlas. CSF1 tissue expression.