Date of Graduation


Document Type


Degree Name

Bachelor of Science

Degree Level



Chemistry & Biochemistry


Stenken, Julie

Committee Member/Reader

Mazzanti, Chris

Committee Member/Second Reader

Lee, Richard

Committee Member/Third Reader

Caldwell, Stephen


Microdialysis sampling involves the collection of biological fluids from tissues or fluid-filled cavities in vivo via diffusion through a semipermeable membrane probe. In order to increase the recovery of fluids for analysis from this process, a new regime was attempted that would allow perfusion fluids to make multiple passes through the probe in order to collect more analyte with each additional pass. This was dubbed the Bidirectional Flow Technique. Dextran-70 solution was used as the perfusion fluid while 100μM Methyl Orange solution was used as the analyte. The experiments were performed in vitro using a fully automated microdialysis ePump capable of performing the bidirectional fluid pushing and pulling. Samples were collected on a range of 1-11 passes of perfusion fluid through the membrane. The recovery of analyte increased with each addition of two passes at rates averaging to a linear progression of +5.45% recovery per added pass. Upon further experimentation, it was noted that the amount of analyte recovered from the backwards passes was far lower than that of the forward passes, a phenomenon thought to be an effect observed due to the construction of the semipermeable probe having not been built with this type of passing regime in mind.