Jun 01, 2026
Intraperitoneal LPS or Poly(I:C) injection and monitoring of mice
- Amandine Even1,2,3,4,5,
- Sriparna Mukherjee1,2,3,5,
- Louis-Eric Trudeau1,2,3,5,6,4
- 1Department of pharmacology and physiology, Faculty of Medicine, Université de Montréal;
- 2Neural Signaling and Circuitry research group (SNC);
- 3Center for Interdisciplinary Research on the Brain and Learning (CIRCA);
- 4Institut Courtois d’innovation biomédicale;
- 5Aligning Science Across Parkinson’s (ASAP) Collaborative Research Network, Chevy Chase, MD, 20815;
- 6Department of neuroscience, Faculty of Medicine, Université de Montréal
Protocol Citation: Amandine Even, Sriparna Mukherjee, Louis-Eric Trudeau 2026. Intraperitoneal LPS or Poly(I:C) injection and monitoring of mice. protocols.io https://dx.doi.org/10.17504/protocols.io.5qpvoe1obl4o/v1
License: This is an open access protocol distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Protocol status: Working
We use this protocol and it's working
Created: March 30, 2026
Last Modified: June 01, 2026
Protocol Integer ID: 314140
Keywords: systemic inflammation, LPS, Poly(I:C), intraperitoneal injection, immune challenge, PAMPs, intraperitoneal injections of lp, intraperitoneal lp, using intraperitoneal injection, induction of systemic inflammation, like immune responses in vivo, sepsis scoring, injection procedure, like immune response, injection, monitoring of mice, lp, mice
Funders Acknowledgements:
Aligning Science Across Parkinson's
Grant ID: ASAP-000525
Abstract
This protocol describes the induction of systemic inflammation in mice using intraperitoneal injections of LPS or Poly(I:C). It includes drug preparation, injection procedures, post-injection monitoring (sepsis scoring and body weight) over several days. This approach is used to model bacterial-like and viral-like immune responses in vivo.
Materials
Drugs:
| A | B | C | |
| Drugs | Cat | Provider | |
| LPS from E.coli O111:B4 | tlrl-eblps | Invivogen | |
| High molecular weight Poly(I:C) | tlrl-pic | Invivogen | |
| Saline | 184-116 | Kimberly Clarck |
Material:
- U-100 Insulin Syringe, with Micro-Fine Intravenous Needle
- 1mL Syringe with Needle
- Scale
Drug preparation
10m
LPS from E.coli O111:B4 was reconstituted at 5 mg/mL in the provided endotoxin-free water and frozen at -20 °C .
The day of the experiment, LPS was diluted at 1 mg/mL in saline.
High molecular weight Poly(I:C) was reconstituted at 1 mg/mL in the provided endotoxin-free physiological water (NaCl 0.9%), heated for 00:10:00 at 65-70 °C , slowly cooled down and frozen at -20 °C .
10m
Injection
Mice were weighted and injected intraperitoneally at
- 3 mg/kg for LPS (3 µL/g ) with an insuline syringe
- 20 mg/kg for Poly(I:C) (20 µL/g ) with a 1mL syringe
Control mice received saline (at 3 µL/g or 20 µL/g ).
Sepsis scoring
Sepsis scoring, based on the table below, was conducted blindly at 6h and 3 days following each injection.
| A | B | C | D | |
| Score | Fur appearance | Level of consciousness and response to stimulus | Eyes | |
| 0 | Coat is smooth | Mouse is active and responds immediately to touch | Eyes open | |
| 1 | Coat is globally smooth with possible patches of piloerected hair | Mouse is active but slow in response to touch | Eyes open, with possible secretions | |
| 2 | Multiple patches of piloerected hair | Mouse is active but slow in response to touch | Eyes not fully open, with possible secretions | |
| 3 | Majority of hair on the back is piloerected | Mouse activity is noticeably slowed but still ambulant[LT1] [AE2] | Eyes not fully open with secretions | |
| 4 | Piloerection may or may not be present, mouse appears “puffy” | Activity is impaired and no response to touch | Eyes closed or milky |
Sepsis scoring criteria to assess the severity of disease after PAMP injection (inspired from Shrum et al, 2014)
Body weight
Mice were monitored for their body weight before the injection and 3-5 days following each injection.
Protocol references
Shrum, B., Anantha, R.V., Xu, S.X., Donnelly, M., Haeryfar, S.M., McCormick, J.K., Mele, T., 2014. A robust scoring
system to evaluate sepsis severity in an animal model. BMC Res Notes 7, 233.
https://doi.org/10.1186/1756-0500-7-233