Rat Interleukin-12 p40 protein (Recombinant) (STJP000666)

What it means: Insect Cells (Sf9) — this protein was produced using a Insect Cells (Sf9) recombinant expression system, which determines its post-translational modification profile, folding, and application suitability.

Why it matters:

• Mammalian systems (HEK293) enable human-like glycosylation and disulfide bond formation — important for receptor-binding assays and cell-based activity studies.
• Insect cell systems (Sf9) offer high-yield expression with partial glycosylation; E. coli systems yield non-glycosylated protein at high quantity.

How to interpret here: For applications requiring native-like glycosylation, Insect Cells (Sf9)-expressed protein is preferred. For structural studies or antibody production where glycosylation is not critical, E. coli or insect cell proteins are suitable.

What it means: >95%, as determined by SDS-PAGE and HPLC — purity was assessed by SDS-PAGE (and HPLC where stated) to confirm the proportion of the preparation that is the correctly-sized target protein.

Why it matters:

• High purity (>95%) minimises background from host cell contaminants in sensitive assays such as SPR/BLI, activity assays, and cell-based studies.
• Consistent lot-to-lot purity is essential for reproducibility in assay development and quantitative experiments.

How to interpret here: >95%, as determined by SDS-PAGE and HPLC means this preparation is suitable for most research applications. Lot-specific purity data (gel image or HPLC trace) is available on the Certificate of Analysis. Contact technical support if ultra-high purity (>99%) is required for biophysical measurements.

What it means: Store at −20°C long-term — this is the recommended condition to maintain peptide or protein integrity, stability, and research-grade performance over time.

Why it matters:

• Storage at −20°C minimises hydrolysis, oxidation, and other degradation reactions that accelerate at higher temperatures.
• Adhering to the stated storage condition is required to maintain the validity of Certificate of Analysis QC data.

How to interpret here: Place the product at −20°C immediately upon receipt. For frequently used products, prepare small working aliquots to avoid repeatedly freeze-thawing the bulk stock.

Tip: Do not store thawed product at 4°C for more than 48 hours. Avoid ultra-low (−80°C) storage unless specified, as some formulations are sensitive to this temperature.

What it means: This peptide is supplied in aqueous solution — Lyophilised from 0.2 Mu m filtered PBS solution.. This formulation preserves peptide stability for use in immunodepletion and competition assays.

Why it matters:

• Ready to use in standard antibody pre-incubation protocols without buffer exchange or reconstitution.
• PBS formulation is compatible with most immunoassay buffers; up to 5% DMSO may be added for poorly soluble peptides.

How to interpret here: Use this peptide directly at a 5–10 molar excess over the antibody concentration. No reconstitution is required. Prepare single-use aliquots upon receipt to preserve the stock.

What it means: UniProt accession Q91ZK7 is the stable, unique identifier for this protein sequence and annotation record in the Universal Protein Resource (UniProtKB) database.

Why it matters:

• The UniProt entry provides the canonical sequence, known isoforms, post-translational modification sites, disease associations, and curated literature.
• Cross-referencing results to UniProt enables standardised data reporting and database integration (PDB, STRING, OMIM, Ensembl).

How to interpret here: Use UniProt ID Q91ZK7 at uniprot.org to retrieve the full sequence, confirm the expressed region covered by this product, and verify which isoform is represented. The accession is also useful for downstream bioinformatic analyses.