Dried blood spots (DBS) have been used for many years in neonatal testing using either a heel or finger prick onto a piece of paper which is then dried and shipped for analysis. This approach has now been applied to the field of bioanalysis in preclinical, toxicokinetic, and clinical studies. DBS has several benefits, namely:

• The use of low sample volumes allows pediatric sampling, improves study recruitment
• All toxicokinetic data can be derived from samples from one animal, improving data quality
• Reduces cost in animals, procedures and test substances
• Cards can be stored at ambient conditions, reducing sample storage and transport costs

One major difference between the neonatal studies and bioanalytical studies is the rigorous quantitative nature of the bioanalytical studies. Although there are many benefits of the DBS approach for the bioanalyst, both ethical and financial, the use of DBS involves a reconsideration of current workflows. Notably, the small volumes typical of the DBS sample require highly-sensitive LC/MS/MS assays. Thus, the area of dried blood spot analysis is attracting a significant amount of research into best practices.