Description
Product Overview
SeamlessBio Normal Rabbit Serum (NRS) is collected from healthy, non-immunised Oryctolagus cuniculus rabbits sourced from controlled EU facilities, sterile filtered at 0.2 µm, and supplied with full batch documentation. NRS is the standard blocking reagent for immunohistochemistry (IHC), immunofluorescence (IFA), and ELISA protocols employing rabbit primary antibodies — it saturates non-specific secondary antibody binding sites and suppresses background signal in tissue sections and microplate assays. Available in volumes from 1 mL to 100 mL; heat-inactivated and pre-immune formats available on request.
Technical Specifications
| Parameter | Specification |
|---|---|
| Species | Oryctolagus cuniculus (domestic rabbit) |
| Designation | Normal Rabbit Serum (NRS) |
| Immunisation status | Non-immunised (no defined antigen exposure) |
| Sterile filtration | 0.2 µm membrane filtration |
| Origin | EU — controlled housing facilities |
| Heat inactivation | Standard: not heat-inactivated; HI (56 °C, 30 min) available on request |
| Haemolysis | Slight to none |
| Storage | −20 °C long-term; +4 °C short-term (stable up to 4 weeks) |
| Shelf life | Min. 12 months from manufacture date |
| Documentation | CoA, CoO, SDS — batch-specific |
Applications
| Application | Description |
|---|---|
| IHC / IFA blocking | 2–10% NRS blocking step prior to rabbit primary antibody incubation — reduces non-specific secondary antibody binding in tissue sections and cell preparations |
| ELISA development | Background suppression in sandwich and competitive ELISAs using polyclonal rabbit antibodies — standard 1–5% NRS blocking in well coating or detection step |
| Western blot blocking | Alternative to BSA or milk powder for blotting protocols with rabbit pAbs — particularly where milk-based blockers interfere with phospho-antibody specificity |
| Species-specificity controls | Negative control serum to confirm secondary antibody species-specificity in multi-species or dual-label immunofluorescence experiments |
| Pre-immune / isotype control | Pre-immune rabbit serum collected before antigen challenge — used in parallel with immune serum to confirm antigen-specific response in polyclonal antibody production |
Available Formats
| Format | Volume |
|---|---|
| Bottle | 1 mL |
| Bottle | 5 mL |
| Bottle | 10 mL |
| Bottle | 50 mL |
| Bottle | 100 mL |
| Bulk | On request |
Key Benefits
Batch Reservation
Reserve validated lots up to 36 months for reproducible long-term IHC, IFA, and ELISA workflows.
Full Documentation
CoA, CoO and SDS — from ISO 9001 and ISO 13485 certified partner facilities. Additional documents on request.
EU & Swiss Supply
Sourced from certified EU partner facilities — fast cold-chain delivery across EU, UK and Switzerland.
Frequently Asked Questions
What is the difference between Normal Rabbit Serum (NRS) and pre-immune rabbit serum?
Normal Rabbit Serum (NRS) is collected from non-immunised rabbits with no defined antigen exposure — it contains a broad background of rabbit immunoglobulins with no specific antibody against a defined target. Pre-immune serum is collected from the same individual rabbit immediately before immunisation with a specific antigen, establishing the baseline antibody background for that animal. Pre-immune serum is used as the matched negative control in polyclonal antibody production experiments, confirming that any signal observed with the immune serum is antigen-specific. SeamlessBio NRS is suitable for standard blocking applications; pre-immune rabbit serum is available on request.
At what concentration should Normal Rabbit Serum be used for IHC and IFA blocking?
The standard working concentration for NRS blocking in IHC and IFA is 2–10% (v/v) in phosphate-buffered saline (PBS) or TBS, applied for 30–60 minutes at room temperature prior to primary antibody incubation. The optimal concentration depends on tissue type, fixation method, and secondary antibody. Higher concentrations (5–10%) are recommended for tissues with high non-specific binding potential (liver, kidney, lymph node). Always use NRS from the same species as the secondary antibody — in this case, a rabbit-derived secondary antibody system — to maximise blocking efficacy. Titration at the outset of protocol development is recommended to balance background suppression with signal preservation.
Is heat-inactivated Normal Rabbit Serum available, and when is it needed?
Yes — heat-inactivated NRS (56 °C, 30 minutes) is available on request. Heat inactivation denatures complement proteins in the serum, which is required when complement activity would interfere with the assay — for example, in complement fixation tests (CFT), cytotoxicity assays, or certain cell-based protocols where complement-mediated lysis must be excluded. For standard IHC, IFA, and ELISA blocking applications, non-heat-inactivated NRS is preferred, as the complete protein content provides more effective background suppression. Contact us with your protocol requirements to confirm the appropriate format.
Can Normal Rabbit Serum be used as a blocking reagent with anti-rabbit secondary antibodies?
Yes — this is the primary application of NRS. When using an anti-rabbit secondary antibody (e.g., goat anti-rabbit IgG conjugated to HRP or a fluorophore), pre-blocking with 2–10% NRS saturates non-specific binding sites on the tissue or membrane surface, preventing the secondary antibody from producing background signal at sites where no primary antibody is bound. It is critical to use NRS (rabbit origin) specifically when the secondary antibody targets rabbit immunoglobulins — using serum from the same species as the host of the secondary antibody is a distinct protocol that would introduce cross-reactivity.
What other animal sera does SeamlessBio supply for blocking and immunoassay applications?
SeamlessBio supplies a full range of normal animal sera for IHC, IFA, ELISA, and complement applications, all sterile filtered at 0.2 µm with full CoA, CoO, and SDS documentation: Normal Mouse Serum (NMS), Normal Rat Serum (NRS-rat), Normal Goat Serum (NGS), Normal Sheep Serum (NSS), Normal Chicken Serum (NCS), Pig Serum, Horse Serum / Donkey Horse Serum (DHS), and Guinea Pig Serum (for complement fixation tests — CFT). All formats are available in volumes from 1 mL to 100 mL, with bulk supply on request. See the full Animal Sera portfolio for the complete range.
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48h response · EU & Swiss Supply · Batch reservation available · Full documentation
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