Recombinant LASV Nucleoprotein Protein, N-His & C-His

What it means: Target names the protein this product represents. Here the target is Nucleoprotein — the nucleoprotein (NP) of Lassa virus.

Why it matters:

• LASV encodes the nucleoprotein on the S segment of its genome, in the opposite orientation to the glycoprotein precursor on the same segment.
• The nucleoprotein is the most abundant viral protein in infected cells, which is why it is commonly used as a coating antigen and as an immunogen.
• Target and Species are separate fields: Nucleoprotein is the protein, Lassa virus is the virus it comes from.

How to interpret here: A target of Nucleoprotein means this product represents the LASV nucleoprotein and not the glycoprotein subunits GP1 and GP2, which come from a separate gene on that segment.

Tip: When comparing the same target from different suppliers, compare the residue range and the accession, not only the target name.

What it means: Species states the organism the protein sequence comes from. For this product the species is Lassa virus (LASV), a mammarenavirus.

Why it matters:

• Arenavirus nucleoprotein sequences are related across the family, so the species tells you the source sequence, not how selective the protein will be in serology.
• Lassa virus itself exists as several genetically distinct lineages; the manufacturer cites one accession (P13699) and does not state how the sequence compares with other lineages.
• Other arenaviruses have their own nucleoprotein sequences and are not covered by this product.

How to interpret here: Read Lassa virus as the source of the sequence. Cross-reactivity with antibodies raised against other arenaviruses is not characterised by the manufacturer for this product; do not assume it in either direction.

Tip: Record the accession alongside the species when comparing antigens across suppliers.

What it means: Expression Region gives the first and last residues of the expressed sequence. The value shown here is Met1-Leu569, numbered by the manufacturer on accession P13699.

Why it matters:

• The manufacturer gives the range as Met1-Leu569, numbered on the cited entry.
• The His tags are additional sequence at the termini and are not part of this range.
• The range tells you which part of the parent sequence is present, which matters for epitope coverage and for comparing products.

How to interpret here: Treat Met1-Leu569 as the definition of what is in the vial, and check that it covers the epitope or domain your assay depends on.

Tip: No predicted molecular weight is stated for this product, so establish the expected band size on SDS-PAGE yourself before relying on the protein as a standard.

What it means: Expression system is the host used to produce the recombinant protein. This protein is expressed in E. coli.

Why it matters:

• E. coli gives high yield at low cost and is widely used for antigens intended for ELISA, immunisation and Western blot.
• Proteins made in E. coli carry no glycosylation, so epitopes that depend on sugar groups are not reproduced; that limitation bears on viral glycoproteins rather than on an internal protein such as the nucleoprotein.
• Proteins purified from E. coli can carry traces of host-cell material; the stated purity for this product is >90% as determined by SDS-PAGE.

How to interpret here: E. coli is the host behind the listed uses (ELISA, immunogen, SDS-PAGE, Western blot). For assays that depend on the native structure of the virus particle, check performance in your own system.

Tip: Endotoxin is not stated for this product; ask before using it in cell-based work.

What it means: Tag describes the fusion sequence added for purification or detection. This protein carries N-His & C-His, a polyhistidine tag at each terminus.

Why it matters:

• A His tag allows capture on nickel or cobalt resins and detection with anti-His antibodies.
• The tags are additional sequence outside the expressed range (Met1-Leu569), one at the N-terminal end and one at the C-terminal end of the construct.
• Having a tag at both ends means a terminal tag is still present if one end is lost to proteolysis, but it also adds sequence at both termini.

How to interpret here: With tags at both termini you can use anti-His reagents as a control readout in ELISA or Western blot, alongside antibodies specific for the target.

Tip: If you detect with anti-His reagents, remember that both termini carry a tag, so a His signal does not tell you which end of the protein is intact.

What it means: Purity states how much of the total protein runs as the expected band. This product is >90% as determined by SDS-PAGE.

Why it matters:

• Purity by SDS-PAGE describes protein composition only; it does not measure endotoxin, activity or aggregation.
• For coating ELISA plates or immunising animals, higher purity reduces, but does not remove, background signal and unwanted immune responses caused by host-cell proteins.
• Up to 10% of the protein may be other proteins, including host-cell proteins or truncated forms, and endotoxin is not stated, so include suitable controls.

How to interpret here: Read >90% as determined by SDS-PAGE as a minimum specification; contact us if you need an exact purity value.

Tip: Purity and identity are different questions; confirm the expected band in your own SDS-PAGE or Western blot before relying on the protein.

What it means: Form is the physical state of the product as shipped. This protein is supplied as a Lyophilized (freeze-dried) powder, from a solution in PBS pH 7.4, 1 mM EDTA, 4% Trehalose, 1% Mannitol.

Why it matters:

• A lyophilized protein must be reconstituted before use; the manufacturer does not state a concentration, so the volume of water you add sets the stock concentration.
• Mix gently after adding sterile water; do not vortex or pipette up and down.
• After reconstitution, store single-use aliquots to avoid repeated freeze-thaw cycles.

How to interpret here: Plan to reconstitute the lyophilized powder in sterile water, let it sit for at least 15 minutes with gentle agitation, then aliquot for storage.

Tip: Centrifuge the vial briefly before opening so that no powder is lost from the cap or walls.