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Updated: Apr 6, 2026
Intravital Microscopy of the Mouse Brain Microcirculation using a Closed Cranial Window
Published on: November 18, 2010
IV and IP administration of rhodamine in visualization of WBC-BBB interactions in cerebral vessels
Zachary Wilmer Reichenbach1,2, Hongbo Li1,2, John P Gaughan3
1Temple University School of Medicine, Center for Sustance Abuse Research, Philadelphia, Pennsylvania, 19140.
Insights
Intraperitoneal (IP) injection of Rhodamine 6G is as effective as intravenous (IV) injection for intravital microscopy of leukocyte-endothelial interactions in brain pathologies. This IP method offers a viable, less complicated alternative for researchers.
Area of Science:
- Neuroscience
- Immunology
- Microscopy
Background:
- Intravital fluorescence microscopy visualizes leukocyte-endothelial interactions in brain pathologies.
- Intravenous (IV) dye injection, like Rhodamine 6G, poses technical challenges and complications.
- Alternative administration routes are needed to simplify experimental procedures.
Purpose of the Study:
- To evaluate the efficacy of intraperitoneal (IP) Rhodamine 6G injection for intravital microscopy.
- To compare IP versus IV injection of Rhodamine 6G for studying leukocyte-endothelial interactions.
- To determine if IP injection is a viable alternative to IV injection in cerebral pathology research.
Main Methods:
- Utilized epi-illuminescence intravital fluorescence microscopy through a cranial window.
- Administered Rhodamine 6G via both IP and IV routes in experimental animals.
- Analyzed rolling and adherent leukocytes and quantified cell detection using flow cytometry.
Main Results:
- No significant difference was observed in detecting rolling or adherent leukocytes between IP and IV Rhodamine 6G administration.
- Flow cytometry analysis confirmed comparable cell detection capabilities for both injection routes.
- IP injection proved as efficacious as IV injection for intravital microscopy.
Conclusions:
- Intraperitoneal Rhodamine 6G is an effective and viable alternative to IV administration for intravital microscopy.
- This method simplifies experimental design and reduces potential complications associated with IV access.
- Facilitating intravital studies can accelerate research into cerebral pathologies and clinical translation.
Abstract:
Epi-illuminescence intravital fluorescence microscopy has been employed to study leukocyte-endothelial interactions in a number of brain pathologies. Historically, dyes such as Rhodamine 6G have been injected intravenously. However, intravenous injections can predispose experimental animals to a multitude of complications and requires a high degree of technical skill. Here, we study the efficacy of injecting Rhodamine 6G into the peritoneum (IP) for the purpose of analyzing leukocyte-endothelial interactions through a cranial window during real time intravital microscopy. After examining the number of rolling and adherent leukocytes through a cranial window, we found no advantage to the intravenous injection (IV). Additionally, we tested blood from both routes of injection by flow cytometry to gain a very precise picture of the two methods. The two routes of administration failed to show any difference in the ability to detect cells. The study supports the notion that IP Rhodamine 6G works as efficaciously as IV and should be considered a viable alternative in experimental design for investigations employing intravital microscopy. Facilitated intravital studies will allow for more exploration into cerebral pathologies and allow for more rapid translation from the laboratory to the patient with less chance of experimental error from failed IV access.
