Microdialysis and its Application:
Microdialysis is primarily being used as an advanced technique for in vivo sampling of virtually any soluble small molecular weight substances from interstitial fluid (ISF). Microdialysis has a wide range of applications including monitoring and quantification of neurotransmitters, neuropeptides and hormones in the brain and periphery, absorption and distribution of metabolites, and receptor agonist or antagonist and other molecules in extracellular space etc 1-2. Recently, microdialysis has also been explored as a potential technique as an in situ sample pre-treatment for environmental assays including organic and inorganic effluents and soil solutions3-5.
The Process of Microdialysis:
The technique is minimally invasive and requires the stereotactic insertion of a thin tube (lined with a dialysis membrane), called microdialysis probe, into the targeted area. The probe is continuously perfused with a physiological solution (perfusate) at a low flow rate of 0.1-1.0 μL/min as required (Figure 1). The ionic composition of the solution closely resembles the surrounding interstitial fluid. Microdialysis, a bi-directional technique, allows both sampling and delivery of endogenous (e.g., neurotransmitters) and exogenous (e.g., drugs) analytes of interest respectively. The flow direction of the analyte depends on their concentration gradient6. The analyte leaving the probe is called dialysate and is collected periodically for the subsequent analysis. Research studies revealed that the membrane of the microdialysis probe and the flow rate of the perfusion (physiological solution) are important factors in various microdialysis procedures7. Using a syringe pump for microdialysis allows for accurate flow and minimize human handling error.
Figure 1: Schematic diagram of: a microdialysis probe (b), microdialysis process technique (the semipermeable membrane of the microdialysis probe restricts the diffusion of large molecules such as red blood cells, large proteins and virus)8.
How to Choose Syringe Pumps for Microdialysis Technique:
If you would like to achieve reliable and reproducible results, the syringe pump interfaced with microdialysis probe must be highly accurate and precise to control the flow rate of the analyte ranging from 0.001 µL/min to 1.0 mL/min. When you select a syringe pump for a microdialysis technique, it is also important to make sure that it is capable to sample and deliver a wide range of analyte including stereotaxic, radioactive and environmental materials etc.
Chemyx NanoJet syringe pump is efficiently designed to deliver all the aforementioned features and hence, is an ideal tool for the highly sensitive applications of microdialysis techniques such as pharmacodynamics, pharmacokinetics, clinical and environmental studies9-10.
- Chefer, V. I., Thompson, A. C., Zapata, A. and Shippenberg, T. S. 2009. Overview of Brain Microdialysis. Current Protocols in Neuroscience. 47:7.1:7.1.1–7.1.28
- Carter, M. and Shieh, J. 2015. Stereotaxic Surgeries and In Vivo Techniques, In Guide to Research Techniques in Neuroscience (2nd Edition), pp. 73-88, Academic Press-Elsevier
- Manuel, M., Wolfgang, F. 2005. The potential of microdialysis as an automatic sample-processing technique for environmental research. TrAC Trends in Analytical Chemistry. 24 (4): 324–333
- Nelson, T., Jonas, M. and Gerald, M. 2002. A study of microdialysis sampling of metal ions. Analytica Chimica Acta. 456 (2): 253–261
- Erich, I., Jonas, Ö., Sandra, J., Kerstin, H. and Torgny, N. 2011. The potential of microdialysis to monitor organic and inorganic nitrogen compounds in soil. Soil Biology and Biochemistry. 43 (6): 1321–1332
- Chaurasia, C.S., Müller, M., Bashaw, E.D., Benfeldt, E., Bolinder, J., Bullock, R., Bungay, P.M., DeLange, E.C., Derendorf, H., Elmquist, W.F., Hammarlund-Udenaes, M., Joukhadar, C., Kellogg, D.L. Jr., Lunte, C.E., Nordstrom, C.H., Rollema, H., Sawchuck, R.J., Cheung, B.W., Shah, V.P., Stahle, L., Ungerstedt, U., Welty, D.F. and Yeo, H. 2007. AAPS-FDA Workshop White Paper: Microdialysis Principles, Application and Regulatory Perspectives. Pharm Res. 24 (5): 1014–25
- Penicaud, L., Benani, A., Datiche, F., Fioramonti, X., Leloup, C. and Lienard, F. 2013. Animal Models and Methods to Study the Relationships between Brain and Tissues in Metabolic Regulation, In Animal Models for the Study of Human Disease, pp. 569–593, Academic Press-Elsevier
- Priya, R.S. and Córcoles, E.P., 2012. Microdialysis Monitoring of Biomarkers for Early Recognition of Intestinal Ischemia, In “Sepsis – An Ongoing and Significant Challenge”. Azevedo, L. (Ed.), Chapter 10, InTech, DOI: 10.5772/50240. Available from: https://www.intechopen.com/books/sepsis-an-ongoing-and significant-challenge/microdialysis-monitoring-of-biomarkers-for-early-recognition-of-intestinal-ischemia)
- NanoJet Stereotaxic Syringe Pump. 2017. Retrieved from https://www.chemyx.com/syringe-pumps/nanojet/
- Elmquist, W.F. and Sawchuk, R,J. 1997. Application of microdialysis in pharmacokinetic studies. Pharm Res.14(3):267-88