Tubing options got you twisted?

Posted on 25 May 2021 by Starlette Douglass

Are you new to microdialysis sampling and confused by all the tubing options available? Have you been performing microdialysis studies for years, but are unsure of alternative tubing options? Or maybe you are somewhere in between. Most times microdialysis tubing is considered an accessory; however, the tubing you choose can make or break an experiment. Choosing the right tubing for your experimental conditions is imperative to a successful outcome.

BASi offers two microdialysis tubing options and one tubing option for open flow microperfusion.  Open flow microperfusion is a technique like microdialysis but requires specialized tubing. Each of these tubing options, while similar, provide certain characteristics and perform specialized functions.

Microdialysis Tubing

Fluorinated ethylene-propylene, or FEP, tubing is the preferred tubing for many laboratories. The small diameter, clear walls, strength, flexibility, and economical price point of FEP tubing lends to viability in a wide variety of techniques. Dead volume is minimized by the small diameter, leading to a decrease in Taylor dispersion and diminished sample degradation. Both effects attribute to a higher-quality sample that has greater temporal resolution. Flow is easier to track during priming and bubbles are readily visualized due to the clear walls of FEP tubing. It has the strength to withstand an awake, freely moving subject without kinking or stretching immediately. Even more, because it is light-weight and flexible, FEP tubing allows the subject unhindered movement. FEP tubing is best suited for techniques using lower pressures, such as syringe pump microdialysis, compared to microdialysis that uses a perfusion pump.

Polyether ether ketone, or PEEK tubing, has been designed as an alternative to FEP tubing for sampling stickier substrates. While it shares some of the qualities of FEP tubing, such as the small diameter, PEEK tubing also has a low oxygen permeability, is opaque, and is available in a variety of colors. The low oxygen permeability of PEEK tubing is good for multiple reasons.  First, it makes it a great choice when working with a compound or analyte that oxidizes.  Second, it makes for a better alternative for push-pull systems using a perfusion pump because it reduces the introduction of bubbles into the microdialysis system. The blue, red, and tan color of PEEK tubing allows for color-coding of experimental setups and immediate identification of inlet and outlet lines.

OFM Tubing

OFM tubing is a low binding tubing designed specifically for the use in open flow microperfusion. OFM tubing possesses the best qualities of FEP and PEEK tubing types. OFM tubing exceeds the strength of FEP tubing, while sharing its clear side walls, great flexibility, and small diameter. It shares the low oxygen permeability and ability to withstand greater internal pressures of PEEK tubing as well. Further, samples are protected by the low binding capacity of the materials while your animals are protected by the gamma sterilized product and lightweight design.

The most important thing when choosing materials is protecting the health and well-being of study animals and sample integrity. In a microdialysis experiment, tubing is essential to achieving both goals. BASi offers an array of tubing for sampling a variety of substrates. Custom lengths are also available upon request.  Should you have any questions regarding the tubing options offered by BASi or to speak with a representative that can help you identify the tubing most suitable for your microdialysis study, please reach out to us at!

Ask BASi:  How does tubing connect to instruments?

Tubing connectors are used to connect tubing to microdialysis probes, syringes, swivels, liquid switches, and fraction collectors.  Silicone and FEP tubing connectors are offered from BASi.  Selection of tubing connectors is based on ID (range from 0.6 to 0.8mm) and tightness of seal required by the application.  Contact BASi to request more information about the tubing connectors that will work best with your application!

Helpful Definitions

Dead Volume: The internal volume of the parts of the microdialysis setup.

Taylor Dispersion: The broadening of sample zones within a microdialysis setup due to flow and diffusion.

Priming: The act of pre-filling the components of the microdialysis setup in preparation for a microdialysis run.

Disclaimer: The information contained in this post represents the views and opinion of the author and does not necessarily represent the views or opinions SUNY University at Albany or the Research Foundation of SUNY.   

Starlette Douglass on LinkedIn

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