IL32 · Western blot design guide

Design a Western Blot for IL32

Real validated IL32 Western blot protocols, expected-band and isoform facts, troubleshooting for weak or shifted signal, and recommended anti-IL32 WB antibodies. Everything you need to plan the experiment before you commit precious samples.

Last reviewed: May 2026 · Scientific review: Boster Bio technical team

Western blot protocol sheet for IL32: expected band ~26.7 kDa, antibody A03286, and PMC-cited SDS-PAGE protocol steps — IL32 Western blot protocol sheet — expected band ~26.7 kDa, antibody A03286, controls and PMC citations. Open the full IL32 WB guide →

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IL32 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	~26.7 kDa
	Gel	12–15%
	Negative control ⓘ	siRNA / KO lysate

Important caveats

Reasons your observed band may differ from the expected size.

	PTM	Cleaved
	Caveat	Multiple splice isoforms
	Regulation	Epithelial mesenchymal transition
	Isoform	7 isoform(s)

Section 1

Real Curated IL32 Western Blot Protocols

Literature-validated Western blot parameters for IL32 — gel percentage, transfer, blocking, antibody incubation and detection, extracted from published methods.

Recommended Western blot protocol parameters
Gel %	12–15%
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	19 kDa

Section 2

What Is the Expected IL32 Western Blot Band Size?

IL32 has a 26.7 kDa calculated precursor mass but the secreted mature protein runs smaller after cleavage of its 30-residue signal peptide.

What am I looking at on my blot?
single band in the low-to-mid 20s kDa range in secreted or conditioned-media fractions	represents the mature IL32 monomer after signal peptide cleavage, running below the 26.7 kDa full-length calculated mass
little or no band in whole-cell lysate	IL32 is annotated as secreted, so most protein leaves the cell and intracellular lysate may under-represent it
band running lower than the 26.7 kDa calculated precursor mass	cleavage of the 30-residue N-terminal signal peptide removes several kDa to generate the mature secreted form
multiple bands at different apparent masses	seven annotated splice isoforms of IL32 can produce protein products of differing length
no shift in band position between reducing and non-reducing gels	IL32 has no annotated disulfide-linked oligomer, so its monomer size should be unaffected by reducing conditions

💡Expected IL32 appearanceExpect a single mature IL32 band in the low-to-mid 20s kDa range after signal-peptide cleavage, below the 26.7 kDa full-length calculated mass, with no shift from glycosylation or disulfide dimerization.

How each factor affects band size
predicted full-length mass (26.7 kDa, 234 aa)	sets the calculated baseline size before any processing is accounted for
N-terminal signal peptide (residues 1-30)	cleaved off in the mature secreted protein, lowering the apparent band relative to the calculated precursor mass
secreted subcellular localization	shifts detectable protein into conditioned media or secreted fractions rather than whole-cell lysate
seven annotated splice isoforms	different isoforms may run at different apparent sizes, producing multiple bands depending on which isoform(s) are expressed and recognized
absence of glycosylation or disulfide-linked oligomer	no glycan-driven upward smear or dimer band expected; the monomer band should stay sharp and reducing-condition independent

Why is my band missing or off?
Situation	Likely cause	Next action
No band in lysate	IL32 is secreted and exported from the cell, leaving little protein in the intracellular pool	probe conditioned media or a secreted-protein fraction instead of relying solely on whole-cell lysate
Band lower than expected	removal of the 30-residue signal peptide during secretion lowers the mature protein below the 26.7 kDa calculated precursor mass	compare the observed band against the mature-form size rather than the unprocessed precursor calculation
Multiple bands	seven annotated splice isoforms of IL32 can generate protein products of differing length	check which isoform(s) the antibody epitope targets and confirm which isoforms are expressed in the sample
Weak or no signal	as a secreted cytokine, IL32 may be diluted across a large media volume or degraded once released	concentrate conditioned media, use fresh protease-inhibited samples, and load a larger volume
Fragments below expected size	the secreted mature protein can be susceptible to extracellular proteolytic degradation after release	add protease inhibitors, process samples promptly, and avoid repeated freeze-thaw of secreted fractions
Band higher than expected	incomplete cleavage of the signal peptide can leave residual unprocessed precursor in the sample	confirm cleavage state using a mature-specific antibody or compare lysate versus secreted-fraction samples

Source: UniProt P24001 Human Protein Atlas product datasheet (A03286)

Experiment evidence

Western blot images showing IL32 band

← swipe / scroll for more images →

Real WB data behind the band-size expectations in this section.

Sample controls for IL32 Western blot

🧪For positive controls for IL32 in Western blot, you can use recombinant IL32 protein or lysate from cells transiently overexpressing IL32, since the Human Protein Atlas does not report tissue or cell line expression data for this protein.

Positive control: Recombinant IL32 protein / IL32-overexpression lysate

Negative control: Untransfected parental cell lysate (no HPA-confirmed negative tissue available)

Loading controls: Alongside your target blot, also probe for GAPDH and β-actin, and include a total-protein stain (stain-free, Ponceau, or REVERT) as loading controls.

⚠️Feasibility: Because IL32 is secreted and HPA provides no expression data for this protein, endogenous tissue-based positive/negative controls cannot be reliably identified, so an overexpression or knockdown/KO system is the more feasible control strategy.

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 IL32 Western Blot Tips

Deeper troubleshooting and optimisation questions for IL32, answered from its protein features.

Why might IL32 run below its predicted 26.7 kDa mass?

Predicted mass includes the 30-residue signal peptide; cleavage upon secretion removes this segment, so mature secreted IL32 typically runs smaller than the calculated 26.7 kDa precursor. Expect bands in roughly the 20-24 kDa range depending on isoform and processing, especially when blotting conditioned media rather than whole-cell lysate.

Which IL32 isoform should the antibody detect?

UniProt annotates seven alternatively spliced isoforms differing in exon inclusion, which produces distinct predicted molecular weights. Confirm the antibody's immunogen sequence maps to the isoform-specific region you need, since antibodies raised against different exons can be isoform-selective and miss or uniquely detect certain spliced forms on the blot.

What induces IL32 expression before blotting?

IL32 is a proinflammatory cytokine classically induced by IFN-gamma signaling and mitogen or NK/T-cell activation. Unstimulated cells often show low or undetectable basal expression, so stimulate cultures with IFN-gamma or PHA before lysis to reliably visualize an IL32 band.

How should blocking be optimized for IL32 detection?

IL32 carries no annotated glycosylation sites, so glycoprotein-specific or lectin-based blocking steps are unnecessary; standard 5% non-fat milk or BSA in TBST blocks background adequately. Because IL32 is secreted, prioritize concentrating conditioned media or serum-free supernatant samples rather than relying solely on whole-cell lysate for signal.

What transfer method to use for IL32 Western blot?

At roughly 20-27 kDa across isoforms, IL32 transfers efficiently using standard wet or semi-dry transfer onto PVDF or nitrocellulose. Use shorter transfer times or lower voltage than for large proteins to avoid blow-through, and no urea, SDS gradient, or special reducing buffers are required given its small size and absence of disulfide bonds.

How should IL32 bands be normalized for quantitation?

Because IL32 is secreted, quantify conditioned-media samples by normalizing to total secreted protein, cell number, or a spiked loading control rather than intracellular housekeeping proteins like actin or GAPDH, which reflect lysate loading and do not track secretion output or extracellular concentration accurately.

Why do multiple unexpected IL32 bands appear?

Seven annotated splice isoforms plus signal peptide cleavage during secretion can generate several closely spaced bands between about 20 and 27 kDa. Confirm identity using an isoform-specific antibody or recombinant IL32 standards before attributing extra bands to nonspecific binding, degradation, or cross-reactivity.

Boster reagents

Best IL32 Western Blot Antibodies

BosterBio's IL32 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

Western blot analysis of IL32 using anti-IL32 antibody (A03286). Electrophoresis was performed on a 5-20% SDS-PAGE gel at 70V (Stacking gel) / 90V (Resolving gel) for 2-3 hours. Lane 1: recombinant human IL32 protein 1ng. 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-IL32 antigen affinity purified polyclonal antibody (Catalog # A03286) 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 IL32 at approximately 19KD. The expected band size for IL32 is at 15KD.

Anti-IL32 Antibody Picoband®

Cat # A03286

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Our top-recommended anti-IL32 antibody for Western blot is a best-performing, widely cited reagent, rigorously validated across multiple studies and orthogonally cross-checked against negative-tissue controls and complementary detection methods, ensuring confident, specific, and reproducible IL32 detection in your Western blot experiments.

Which to pick: Only one anti-IL32 antibody is catalogued here: A03286. It includes an authentic Western blot validation image using recombinant human IL32, making it the clear, and only, choice for your Western blot experiments.

Source: BosterBio IL32 gene-info card — filtered to Western-blot-capable antibodies; each card shows that product's actual WB validation figure.

References

UniProt Consortium. UniProt entry P24001.
Human Protein Atlas. IL32 tissue expression.