anti-human CD21

What it means: Monoclonal — produced from a single B cell clone, targeting one epitope on the antigen with absolute consistency.

Why it matters:

• Exceptional lot-to-lot reproducibility — every vial binds the same epitope at the same affinity
• Lower non-specific background in most detection formats versus polyclonals
• Required for flow cytometry, quantitative WB, and regulatory-sensitive assays

How to interpret here: This monoclonal antibody delivers consistent, standardized performance — the preferred choice when reproducibility across experiments is critical.

What it means: Host species is Mouse — the animal in which this antibody was raised and produced.

Why it matters:

• Secondary antibody must be anti-Mouse — verify species compatibility with your detection kit
• Do not pair with another primary antibody from Mouse in multiplex staining
• Mouse antibodies follow well-established secondary antibody pairing protocols

How to interpret here: Select an anti-Mouse secondary antibody for indirect detection. For direct conjugate options, check the variant selector.

What it means: Species reactivity of Human, Primate, Horse — the species whose target protein has been validated to react with this antibody.

Why it matters:

• Only use with samples from validated species — unlisted species are not guaranteed
• Cross-reactivity depends on target protein sequence conservation across species
• Confirm species match before ordering when working with non-standard animal models

How to interpret here: This antibody is validated for Human, Primate, Horse samples. For species not listed, check protein sequence homology and consider independent validation.

What it means: Conjugated with Biotin — directly labeled for detection without a secondary antibody.

Why it matters:

• Reduces protocol steps and eliminates secondary antibody cross-reactivity
• Ideal for multicolor flow cytometry panels requiring direct detection
• Simplifies multiplex staining where secondary antibody conflict is a concern

How to interpret here: With Biotin label, detect directly without a secondary antibody. Verify instrument compatibility for your detection channel.

What it means: Isotype IgG1 — the antibody heavy-chain class, which determines secondary antibody requirements.

Why it matters:

• Secondary antibody or detection kit must be specific for IgG1
• Select the matching isotype control for proper background correction in flow cytometry
• IgG subclasses differ in Fc receptor binding, complement activation, and effector function

How to interpret here: Ensure your secondary antibody is specific for IgG1. Use a matched isotype control to assess non-specific background in your assay.

What it means: Validated for FC, WB — confirmed by the manufacturer.

Why it matters:

• Validated applications reflect tested and confirmed conditions for reliable detection
• Non-listed applications require independent validation before routine use
• Each application may need different sample prep, dilution, and detection systems

How to interpret here: Refer to the datasheet for recommended dilution ranges and positive control tissues. For non-listed applications, perform a titration first.

What it means: Clone BU33 — the specific B cell clone from which this monoclonal antibody was derived.

Why it matters:

• Guarantees absolute batch-to-batch consistency — every lot targets the same single epitope
• Literature citations using clone BU33 provide direct cross-lab validation evidence
• RRID or clone citation in publications ensures experimental reproducibility

How to interpret here: The clone BU33 designation is a permanent identifier. Cite this clone name in publications and use it to verify consistency across vendors.