Donkey Serum (Normal Donkey Serum, NDS) — Multiplex IHC Blocking | EU Origin | SeamlessBio
EU Stock0.2 µm sterile filteredNo MOQCoA included
Normal Donkey Serum (NDS) is the preferred blocking reagent for multiplex immunofluorescence panels and IHC protocols that combine secondary antibodies from multiple species. The key advantage: donkeys are phylogenetically distant from the most common laboratory species (mouse, rat, rabbit, goat, sheep) — donkey serum contains no antibodies that cross-react with these species.
When an IHC panel simultaneously uses an anti-rabbit and an anti-goat secondary antibody, neither rabbit nor goat serum can be used (each would interfere with the primary antibody of the other species). NDS is the only correct choice for such multiplex situations — a single blocking step covers all secondary antibody channels.
Applications of Normal Donkey Serum (NDS)
| Application | Protocol | Why NDS? |
|---|---|---|
| Multiplex IHC / IF Blocking | 5–10% NDS in PBS-T, 30–60 min RT — covers all secondary antibody species simultaneously | Donkey does not cross-react with mouse, rat, rabbit, goat, sheep, horse — ideal for multi-label staining |
| Anti-goat + Anti-rabbit combined | Single NDS blocking step before both secondary antibodies | Only solution when protocol requires both anti-goat and anti-rabbit secondaries simultaneously |
| Multiplex antibody diluent | 1–2% NDS in PBS-T as universal diluent | Neutral protein background for all antibody species simultaneously |
| Multiplex Western Blot | 5% NDS in TBST as blocking buffer | No cross-reactivity issue when detecting multiple targets with different species antibodies simultaneously |
| ELISA blocking (multi-species panels) | 2–5% NDS as universal blocker | Suitable when assay combines goat, rabbit, and mouse antibodies |
When NDS instead of NGS or NRS?
| Situation | Correct Serum | Reason |
|---|---|---|
| Only anti-rabbit secondary antibody | NRS (rabbit serum) | Species-matched blocking sufficient |
| Only anti-goat secondary antibody | NGS (goat serum) | Species-matched blocking sufficient |
| Anti-rabbit + anti-goat combined | NDS (donkey serum) ✅ | Donkey does not cross-react with either species |
| Anti-mouse + anti-rabbit combined | NDS (donkey serum) ✅ | Universally neutral toward mouse, rat, rabbit, goat |
| 3-colour multiplex: mouse + rabbit + goat | NDS (donkey serum) ✅ | Only option that covers all three species in one blocking step |
Technical Specifications
| Parameter | Specification |
|---|---|
| Species | Donkey (Equus asinus) |
| Abbreviation | NDS — Normal Donkey Serum |
| Collection | Pooled healthy donors, sterile bleed |
| Filtration | 0.2 µm sterile filtered |
| Origin | EU |
| Storage | −20 °C; aliquoting recommended to minimise freeze-thaw cycles |
| Volumes | 100 mL, 500 mL | Bulk on request |
| Documentation | CoA, CoO on request |
| Options | Heat inactivated (56 °C, 30 min) on request |
| Cross-reactivity profile | No significant cross-reactivity with mouse, rat, rabbit, goat, sheep, horse, human |
Frequently Asked Questions
Why is donkey serum better than goat or rabbit serum for multiplex IHC?
When an IHC panel uses secondary antibodies from more than one species (e.g. anti-rabbit Alexa488 + anti-goat Alexa594), no normal serum from those species can be used as blocker — goat serum would interfere with the anti-rabbit primary, rabbit serum with the anti-goat. Donkey serum is immunologically neutral toward both species and covers the entire panel background in a single blocking step.
What concentration of NDS for multiplex IHC blocking?
5–10% NDS in PBS-T (0.1% Tween-20) for 30–60 minutes at room temperature as blocking step, then proceed directly to primary antibody cocktails without washing. As antibody diluent use 1–2% NDS in PBS-T.
Are there situations where NDS does NOT work?
NDS is not suitable if donkey secondary antibodies are used in the panel — a different neutral serum (e.g. bovine) would be needed. Also, like all normal sera, NDS is not appropriate if the primary antibody itself is derived from donkey.
Complete Animal Serum Portfolio at SeamlessBio
All animal sera from one EU source — consistent documentation, no minimum order.
| Species | Abbr. | Primary Application |
|---|---|---|
| Rabbit | NRS | IHC/WB/ELISA blocking — anti-rabbit secondary antibodies |
| Goat | NGS | IHC/IF blocking — most common secondary antibody host |
| Sheep | NSS | Blocking, complement CFT, vaccine & vet diagnostics |
| Mouse | NMS | ELISA controls, anti-mouse IHC, primary cell culture |
| Rat | — | Anti-rat IHC blocking, rat primary cell culture |
| Horse | DHS | PC12 differentiation, hybridoma, muscle differentiation |
| Chicken | NCS | CEF cell culture, poultry ELISA controls |
| Pig | NPS | Swine vaccine development, porcine vet diagnostics |
| Guinea Pig | NGPS | CFT complement source — unique diagnostic niche |
Order Information
| Parameter | Details |
|---|---|
| Shop URL | shop.seamlessbio.de/en/products/donkey-serum |
| Volumes | 100 mL, 500 mL | Bulk on request |
| Documentation | CoA, CoO on request — free with every order |
| Free test volume | Available before purchase — contact us |
| Batch reservation | Yes — reserve one lot for your entire project |
| info@seamlessbio.de | |
| Phone | +49 851 37932226 |