SA/Streptavidin Protein, HRP

What it means: Target is the identity of the recombinant protein you are purchasing. The target on this page is SA.

How to interpret here: Use SA as your “match checkpoint” before ordering—confirm it aligns with your assay goal (antigen for antibody validation, standard for quantitation, binding partner for kinetics, or functional reagent). The expressed construct is Commercial secret.—verify your epitope/domain is included. Conjugate/tag status is HRP; plan capture/detection and tag controls accordingly. Purity is >90% as determined by SDS-PAGE.—important for low-background binding assays and standards. Physical form is Liquid; plan reconstitution/aliquoting based on this. Storage is Use a manual defrost freezer and avoid repeated freeze thaw cycles. Store at 2 to 8°C for frequent use. Store at -20 to -80°C for twelve months from the date of receipt.—use it to prevent degradation before your run. Choose this when target + origin + construct + handling match your workflow; consider an alternative if you need full‑length vs fragment, a different origin, a different tag, or native PTMs.

Why it matters for buying:

• Biological relevance: Your results depend on whether the protein matches the pathway/epitope/interaction you intend to test.
• Reagent compatibility: Antibodies and ligands can be highly sensitive to construct boundaries, PTMs, and tags.
• Reproducibility: Clear target/construct details reduce “it binds in paper X but not in my hands” surprises.

Practical guidance:

• Confirm the binding site: If you know the epitope or functional domain, verify it overlaps the expressed region before ordering for a critical experiment.
• Plan a pilot: Test a small aliquot first to confirm binding/behavior in your buffer, surface chemistry, and detection method.
• Use controls: Include buffer-only and an unrelated protein control; add a tag-control when a conjugate/tag is present.
• Cell-based awareness: Endotoxin is listed as Please contact with the lab for this information.—important for immune readouts and stimulation assays.
• Buffer compatibility: Formulation is 0.01M PBS, pH 7.4, 50% Glycerol, 0.05% Proclin 300.; confirm it won’t interfere with coating, conjugation, or coupling chemistries.

What to watch out for:

• PTM-dependent epitopes: Proteins expressed in bacteria often lack mammalian glycosylation—choose a host compatible with your epitope/function.
• Tag interference: Tags can create extra epitopes or steric effects; interpret binding with tag controls when needed.
• Construct mismatch: A fragment can be perfect for epitope mapping but may not behave like full‑length protein in functional assays.

What it means: Expression Region describes the exact construct that was expressed and purified (full‑length vs fragment, domains, and sometimes fusions). The value shown here is Commercial secret..

How to interpret here: Treat Commercial secret. as the “what you actually get” definition. For SA, confirm this region includes your binding epitope or functional domain. If a conjugate/tag is present (HRP), confirm the region text doesn’t place it near your binding site. Choose this when your epitope/domain is included; avoid if the region omits critical residues.

Why it matters for buying:

• Epitope inclusion: Many “no signal” outcomes come from ordering a fragment that lacks the epitope.
• Functional behavior: Full‑length and fragments can behave differently in activity assays and conformational binding.
• Immobilization/detection: Fusions/tags can change adsorption and apparent binding kinetics.

Practical guidance:

• Map domains first: If the assay depends on a domain (e.g., kinase domain, extracellular domain), confirm overlap before ordering.
• QC on arrival: Verify size and major species by SDS‑PAGE/Western for critical studies.
• Use construct-matched controls: When comparing variants, keep region and host consistent to reduce confounding.

What to watch out for:

• Missing signal peptides/TM regions: Many constructs omit these; that can change conformation.
• PTM-dependent sites: Fragments expressed in bacteria may not reproduce disulfide patterns or glycosylation.
• Assuming tag position: Do not assume N- vs C-terminal placement unless stated.

What it means: Conjugate describes whether the protein includes a tag or labeling chemistry that changes capture/detection and sometimes solubility. The value shown here is HRP.

How to interpret here: Treat HRP as your capture/detection choice—select it based on how you plan to immobilize the protein, detect it, and control background. This listing is for SA. The construct (Commercial secret.) helps you judge whether the tag may sit near your binding site. Purity >90% as determined by SDS-PAGE. influences background; tag capture can sometimes reduce non‑specific adsorption versus passive coating. Use this tag/conjugate only if you have matching capture/detection reagents and a plan for controls.

Why it matters for buying:

• Workflow fit: Tags can dramatically simplify capture and improve immobilization reproducibility.
• Interpretation: Tags introduce additional epitopes and can change apparent binding kinetics; controls are essential.
• Downstream compatibility: Some downstream chemistries (coupling, labeling) are sensitive to buffer components and tags.

Practical guidance:

• Use tag controls: Include an unrelated protein with the same tag to identify tag-driven background.
• Optimize surface density: Overloading capture surfaces can cause steric crowding and reduce binding.
• Confirm tag location: If your binding site is near a terminus, tag placement can matter—check construct notes.

What to watch out for:

• Tag interference: Tags can mask epitopes or introduce non‑specific binding; compare to tag‑free constructs if needed.
• Assuming cleavability: Do not assume tags are removable unless a protease site/protocol is provided.
• Surface artifacts: Tag capture can change orientation vs passive coating—interpret kinetics accordingly.

What it means: Form describes the physical state of the supplied protein (e.g., lyophilized powder vs liquid solution). The value shown here is Liquid.

How to interpret here: Use Liquid to plan how you will prepare the protein for your assay—reconstitution steps, concentration accuracy, aliquoting, and stability after thawing. Liquid preparations are ready-to-dilute, but they can be more sensitive to freeze–thaw and may contain stabilizers that affect downstream chemistry. Formulation/buffer: 0.01M PBS, pH 7.4, 50% Glycerol, 0.05% Proclin 300. (check compatibility with labeling/coupling and assay buffers). Storage: Use a manual defrost freezer and avoid repeated freeze thaw cycles. Store at 2 to 8°C for frequent use. Store at -20 to -80°C for twelve months from the date of receipt. (aliquot and minimize freeze–thaw). For SA, a pilot dilution series after preparation helps confirm expected behavior.

Why it matters for buying:

• Stability and shipping risk: Lyophilized proteins often tolerate shipping better; liquids can be more temperature-sensitive.
• Concentration accuracy: Incomplete dissolution or pipetting viscous solutions can distort concentrations and assay signals.
• Downstream compatibility: Buffers/stabilizers in liquid formats can interfere with coating, conjugation, or coupling chemistries.

Practical guidance:

• Aliquot immediately: After reconstitution/thaw, aliquot into single-use portions to avoid repeated freeze–thaw.
• Mix gently: Avoid vigorous vortexing for sensitive proteins; gentle inversion or slow pipetting reduces aggregation risk.
• Verify solubility: If you see particulates, allow time to dissolve and consider centrifugation if compatible with your assay.
• Check stabilizers: Glycerol/BSA or preservatives can affect labeling/coupling; buffer-exchange if needed for sensitive chemistries.

What to watch out for:

• Freeze–thaw damage: Multiple cycles can reduce binding/activity and increase aggregation.
• Adsorption losses: Low-concentration proteins can stick to tubes; use low-bind plastics when possible.
• Buffer mismatch: Reconstituting in the wrong buffer can precipitate the protein or alter binding—follow recommended guidance.