Recombinant MACV Nucleoprotein Protein, N-His

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

Why it matters:

• MACV encodes the nucleoprotein on the S segment of its genome, separately from the glycoprotein precursor.
• 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, Machupo virus is the virus it comes from.

How to interpret here: A target of Nucleoprotein means this product represents the MACV nucleoprotein and not the glycoprotein subunits G1 and G2, which the manufacturer catalogues as separate products.

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 Machupo virus (MACV), 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.
• The manufacturer lists reactivity of its matching anti-MACV nucleoprotein antibody with Junin mammarenavirus as well, which indicates shared epitopes within the group.
• Other arenaviruses have their own nucleoprotein sequences and are not covered by this product.

How to interpret here: Read Machupo 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-Leu564, numbered by the manufacturer on accession P26578.

Why it matters:

• The manufacturer gives the range as Met1-Leu564, which starts at the first residue of the cited entry.
• The N-terminal His tag is added outside this range and is not counted in it.
• 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-Leu564 as the definition of what is in the vial, and check that it covers the epitope or domain your assay depends on.

Tip: Confirm the band size on SDS-PAGE against the predicted molecular weight 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.
• 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 an N-His tag, a polyhistidine tag at the N-terminus.

Why it matters:

• A His tag allows capture on nickel or cobalt resins and detection with anti-His antibodies.
• The tag sits outside the expressed range (Met1-Leu564), at the N-terminal end of the construct.
• The manufacturer gives a predicted molecular weight of 65.46 kDa for this product; use it as a guide when reading SDS-PAGE bands.

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

Tip: Antibodies raised against this protein may include anti-His antibodies; account for this when screening against other His-tagged proteins.

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, signal and immune responses from 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; request lot-specific data 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 stock concentration is given on the label or datasheet.
• 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.