The entire system, apart from the Alvetex^® insert, is repeatedly

autoclavable, allowing for sterilization and therefore a high level of

reusability. This bioreactor vessel can be placed on a commercial

magnetic stirrer; however, a custom system is utilized for the

experiments described herein due to the ability to stir a number

of vessels simultaneously and using stir speeds down to 50 rpm.

Figure 3 shows the design of the custom stand to hold the Alvetex^®

inserts. This was designed to promote fluid recirculation through-

out the vessel while protecting the cultures from high levels of shear

stress, however the exact design of this stand can be varied depend-

ing on the desired flow properties. The preferred material for the

Alvetex^® insert holder is PTFE due to its minimal chemical and

biological activity and the ability to withstand multiple autoclave

cycles. The outer vessel was made from glass due to the ease of

production and low costs on top of its biological compatibility and

autoclavability. While a custom lid can be used, a standard 60 mm

petri dish lid may be adequate for successful culture with this

system.

Fig. 3 Schematics for the Alvetex insert. The insert holder has a conical baffle for the lower portion to help

direct fluid recirculation within the vessel while the top of the holder features a notched upper surface to allow

the Alvetex insert to be held in place. Scale bar: 30 mm

244

Henry W. Hoyle et al.