When you need to take repeated blood samples from a rat, consider placing a catheter in the jugular vein or carotid artery and connecting it to a transcutaneous skin button. This method is a refinement over stress-inducing tail vein, jugular or retro-orbital bleeds or other peripheral methods. The Vascular Access Button™ creates a closed system with patency that can extend for weeks and even months.
Furthermore, with a protective aluminum cap, rats can be socially housed, a welfare benefit that is not possible with animals with simple externalized catheters.
Access the button with a syringe fitted with the mating PNP3M injector. Optionally, collect precise microsamples directly into Sarstedt capillary collection tubes by using the PNP3MS connector (arterial pressure is required for best results — for example, from a carotid artery catheterization). For best results always use positive pressure technique when accessing catheters.
To reduce stress even further, collect samples outside the cage: hands-off blood sampling.