- Purpose. Transdermal extraction of clinically relevant analytes offersa potentially non-invasive method of diagnostics. However,development of such a method is limited by the low skin permeability. In thispaper, we report a potential method for non-invasive diagnostics basedon ultrasonic skin permeabilization and subsequent extraction ofinterstitial fluid (ISF) across the skin.Methods. In vivo experiments were performed using Sprague Dawleyrats to assess ultrasound-induced skin permeabilization and subsequentextraction of various analytes. Serum and ISF concentrations of variousanalytes were measured.Results. Application of low-frequency ultrasound rapidly increasedskin permeability. Skin remained in a state of high permeability for atleast three hours. During this period, application of vacuum extractedISF across rat skin in vivo at a rate of 25.7 μl/cm2/hr. We measuredconcentrations of various analytes including glucose, albumin, calcium,urea, triglycerides, lactate, and dextran in transdermally extracted fluid.The composition of the fluid extracted transdermally is similar to thatof ISF.Conclusions. Application of low-frequency ultrasound allows skin permeabilization and extraction of ISF across the skin.