S. Aureus Purified CP5

What it means: This product is a natively purified capsular polysaccharide isolated directly from S. aureus strain Reynolds, not a recombinant or synthetically produced antigen.

Why it matters:

• Native purification from the Reynolds strain preserves the authentic CP5 polysaccharide structure, ensuring serological identity matches clinical isolates used in published OPA assay protocols.
• The Reynolds strain is the reference standard for CP5 in S. aureus vaccine and immunology research — lot traceability back to this strain is critical for inter-study reproducibility.

How to interpret here: This S. aureus CP5 is sourced directly from S. aureus Reynolds, making it the appropriate reference antigen for serotype 5-specific OPA assays and ELISA.

What it means: Form describes the physical state in which the product is supplied. This CP5 is lyophilized (freeze-dried) in sterile water, providing a stable dry-powder format.

Why it matters:

• Lyophilized polysaccharides are more stable at -20°C over extended periods than liquid formulations, reducing hydrolytic degradation.
• Reconstitute in sterile water to your target working concentration before use in ELISA inhibition or OPA assays.
• Aliquot the reconstituted solution into single-use volumes to avoid repeated freeze-thaw cycles.

How to interpret here: This lyophilized S. aureus CP5 requires reconstitution in sterile water prior to use. Store at -20°C before and after reconstitution.

What it means: The target pathogen is Staphylococcus aureus, a leading Gram-positive pathogen responsible for severe bacteremia, endocarditis, and device-associated infections. This product is the serotype 5 capsular polysaccharide (CP5) — a major surface virulence factor.

Why it matters:

• CP5 is expressed by the majority of bacteremic S. aureus isolates alongside CP8 — together they account for ~80% of clinical bloodstream strains.
• S. aureus CP5 is the primary antigen in OPA assays evaluating anti-S. aureus opsonophagocytic antibody function and in ELISA quantification of anti-CP5 IgG.

How to interpret here: Use this S. aureus CP5 antigen for serotype 5-specific immunological assays. For serotype 8 coverage, pair with S. aureus Purified CP8 (BHP20900072).

What it means: Each unit supplies 100 µg of lyophilized S. aureus CP5, which must be reconstituted in sterile water to the desired working concentration before use.

Why it matters:

• Calculating the correct reconstitution volume is essential for reproducible ELISA inhibition and OPA assay results — refer to the lot-specific certificate of analysis for reconstitution guidance.
• Unlike liquid proteins with a pre-defined mg/mL concentration, lyophilized products require a user-defined reconstitution volume; plan this before starting your assay.

How to interpret here: This 100 µg lyophilized S. aureus CP5 unit should be reconstituted in sterile water. Determine the appropriate working concentration empirically for your specific assay system.

What it means: Storage gives the manufacturer-recommended condition for maintaining this product: -20°C, per the IBT Bioservices datasheet.

Why it matters:

• Lyophilized polysaccharides stored at -20°C maintain structural integrity and serological reactivity for extended periods without liquid-phase hydrolytic degradation.
• After reconstitution, aliquot into single-use volumes and return to -20°C to prevent repeated freeze-thaw damage to polysaccharide structure.

How to interpret here: Store this S. aureus CP5 at -20°C both before reconstitution (lyophilized) and after reconstitution (aliquoted). Do not store reconstituted stock at 4°C for extended periods.