Description
Product Overview
SeamlessBio Sheep Serum — Normal Sheep Serum (NSS), EU Origin is collected from healthy, non-immunised Ovis aries, sterile filtered at 0.2 µm, and batch-tested for purity and consistency. Supplied with full lot documentation for use in immunohistochemistry, immunofluorescence, ELISA, flow cytometry, and complement studies.
Normal Sheep Serum is the recommended blocking reagent when sheep-derived antibodies — primary or secondary — are used in immunoassays. It matches the species of the secondary antibody, preventing non-specific binding to endogenous immunoglobulin-binding sites in tissue sections and on cell surfaces. NSS also retains native complement activity, making it suitable as a complement source in haemolytic and functional assays. See the full portfolio on our Animal Sera overview page.
Technical Specifications
| Parameter | Specification |
|---|---|
| Species | Ovis aries (domestic sheep) |
| Designation | Normal Sheep Serum (NSS) — non-immunised donors |
| Origin | EU — controlled collection facilities |
| Filtration | 0.2 µm sterile filtered |
| Mycoplasma | Negative (tested) |
| Storage | –20 °C long-term | +4 °C short-term |
| Shelf life | Min. 12 months from manufacture |
| Options | Heat inactivated (56 °C, 30 min) on request — inactivates complement activity |
| Documentation | CoA, CoO, SDS; additional documents on request |
| Formats | 1 mL, 5 mL, 10 mL, 50 mL, 100 mL; bulk on request |
| Regulatory | Research Use Only (RUO) |
Applications
| Application | Protocol | Note |
|---|---|---|
| IHC / IFA blocking | 2–10% NSS in PBS or TBS-Tween before antibody incubation | Blocks endogenous Fc receptors and non-specific binding sites before sheep secondary antibody incubation — reduces background staining in tissue sections |
| ELISA blocking | 1–5% NSS in assay buffer | Non-specific binding reduction in ELISA formats using sheep-specific detection reagents |
| Flow cytometry | 1–5% NSS for Fc blocking | Reduces non-specific antibody binding in cell surface staining panels with anti-sheep fluorescent conjugates |
| Complement studies | NSS as complement source (non-heat-inactivated) | Retains native complement activity for haemolytic assays, opsonisation studies, and complement fixation protocols — specify non-HI when ordering |
| Cross-reactivity & control matrix | NSS as negative control or competition matrix | Antibody validation against ovine proteins; species-matched serum matrix for ovine diagnostic assays |
Other Animal Sera Available
| Species | Typical Application | Availability |
|---|---|---|
| Rat serum | Immunoassay blocking, cross-reactivity control, rat cell culture | In stock |
| Mouse serum (NMS) | ELISA control, Western blot, hybridoma | In stock |
| Rabbit serum (NRS) | IHC, IFA, ELISA, antibody blocking | In stock |
| Sheep serum (NSS) | IHC blocking, complement studies, anti-sheep secondary | In stock |
| Goat serum (NGS) | IHC, IFA, ELISA, multiplex assays | In stock |
| Chicken serum | IgY assays, cross-reactivity, veterinary diagnostics | In stock |
| Pig serum | Preclinical models, porcine primary cell culture | In stock |
| Horse serum (DHS) | PC-12, hybridoma, insect cells, primary neurons | In stock |
| Guinea pig serum | Complement fixation test (CFT) | On request |
Available Formats
| Format | Size |
|---|---|
| Vial | 1 mL |
| Vial | 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 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
Why use Normal Sheep Serum as a blocking reagent with anti-sheep secondary antibodies?
When a sheep-derived secondary antibody is used in IHC, IFA, or ELISA, tissue sections and cell surfaces contain endogenous proteins that can bind non-specifically to sheep immunoglobulins — producing false-positive background signal. Pre-incubating the sample with 2–10% Normal Sheep Serum (NSS) saturates these non-specific binding sites before the secondary antibody is applied. Because the blocking serum comes from the same species as the secondary antibody, it occupies the binding sites without competing with the primary-secondary detection pair.
Can Normal Sheep Serum be used as a complement source in haemolytic assays?
Yes — non-heat-inactivated NSS retains native complement activity and can be used as a complement source in haemolytic assays, opsonisation studies, and complement fixation protocols. When ordering for complement applications, specify that heat inactivation is NOT required. For blocking applications in complement-sensitive assays, heat-inactivated NSS (56 °C, 30 min) is preferred to avoid unwanted complement activation.
What is the difference between Normal Sheep Serum and immune sheep serum?
Normal Sheep Serum (NSS) is collected from non-immunised, healthy donor animals and contains only background levels of antibodies without deliberate immunisation. It is used as a blocking reagent, control matrix, and complement source. Immune sheep serum is collected after deliberate antigen immunisation and contains high-titre antigen-specific antibodies. SeamlessBio supplies NSS for blocking and research applications; immune sera are a separate product category produced to order.
Is heat-inactivated Normal Sheep Serum available?
Yes — heat inactivation (56 °C, 30 min) is available on request. Heat inactivation destroys complement proteins and is the correct choice for blocking applications in complement-sensitive assays and cell-based protocols where complement activation must be avoided. For complement studies, non-heat-inactivated NSS must be used. Please specify the required form when requesting a quote.
What documentation is supplied with EU Origin Normal Sheep Serum?
Every order includes a Certificate of Analysis (CoA), Certificate of Origin (CoO), and Safety Data Sheet (SDS). Additional documentation — sterility and mycoplasma test protocols — is available on request. Products are handled at ISO 9001 and ISO 13485 certified partner facilities. Batch reservation for up to 36 months is available on request to ensure lot-to-lot reproducibility for long-term assay workflows.
Request a Quote or Sample
48h response · EU & Swiss Supply · Batch reservation available · Full documentation
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