4 top methods of blood collection in lab rodents
by Neoteryx | 2 min read
The methods of blood collection in mice can have varying effects on the animals. Each method requires anesthesia or restraint, depending on the area from which the blood is taken. Certain areas produce more blood during collection, and guidelines prescribe the total amount that can be drawn from a mouse via each method.
1. Venous blood draws from the lateral tail vein or the submandibular vein are usually taken while the mouse is restrained but not anesthetized. Both of these methods require special equipment, and a lateral tail vein draw yields only a small quantity of blood. The submandibular vein is preferred because it's ideal for serial sampling and can draw a moderate amount of blood.
2. Saphenous or retro-orbital vein collection is another way. Both of these collection sites require additional preparation and skill. Extraction from the saphenous vein requires great skill to consistently draw a measurable amount of blood.
Because of the extensive site preparation, the mouse might be more traumatized due to prolonged restraint. The retro-orbital vein can provide medium or large volumes of blood, but the mouse must be monitored within two days after blood collection because visual complications can happen.
3. So-called "terminal" or "non-survival" blood collection is done either pre- or post-mortem and only after the mouse has received surgical anesthesia. Terminal collection can be taken via cardiac puncture and can collect the maximum amount of blood. It can also be done via the aorta or vena cava. Immediately after the blood collection via either of these two methods—and before the mouse recovers from the anethesia—the mouse must be euthanized.
4. Microsampling has the smallest effect on the animal; a very small amount of blood is taken while the mouse has local anesthesia. Volumetric absorptive microsampling (VAMS®) technology enables consistent and accurate blood volume collection (roughly 10 microlitres). VAMS technology provides high-quality and quantitative data while simplifying the blood-collection process as well as the lab procedures required for testing.
The hydrophilic tips of VAMS sampling devices fill after 2-5 seconds of contact with a small amount of blood. This simplifies the sampling method and standardizes the sample volume.
Microsampling is not the preferred extraction method when taking samples from rodents that have tumors or when technical replicates are required. Also, it's difficult to control the bleed rate during sampling, which can result in more blood being taken than can be used in testing.