Preparation of Mouse Plasma Microsamples for LC-MS/MS Analysis Using the Echo Liquid Handler

Serial microsampling of animals reduces the overall number of animals sampled and euthanized for toxicology studies. Traditional composite studies in mice can require up to 700 μL of blood for each time point in a pharmacokinetic study. A draw of 700 μL from a mouse would require the animal to be euthanized and often require the use of addition “satellite” animals to complete the study. Thus, in a 9-point time course analysis of mouse plasma, nine mice would be sacrificed. In response to programs like the EU 3Rs initiative to reduce the use of animals in research researchers have turned to microsampling as an alternative to composite studies. With advances in bioanalytical techniques drug levels can be determined from samples of 20 μL or less. This small sample volume or microsample enables reduces the dependency on satellite animals to complete a study. Additionally, microsampling is faster and less stressful than traditional composite studies.