Rapid Evaluation of Oxygen and Water Permeation through Microplate Sealing Tapes

Abstract

Eight commercially available microplate sealing tapes and 10 other suitable materials (transparent wound dressings) are compared qualitatively in terms of their ability to minimize water evaporation from a multiwell plate while maintaining the oxygen supply as high as possible, which is necessary for applications like aerobic growth. The transparency and sterility of the products are considered as well. All evaluated commercially available sealing tapes fall into one of the following two classes: (1) O(2) transfer is comparable to that of an unsealed plate, but water vapor retention is relatively low, or (2) O(2) transfer via the sealing is slower, but the water retention capability is comparably high. All but one of the evaluated wound dressings fall under the second class. That dressing, however, constitutes a compromise by showing both moderate O(2) permeability and medium water retention. But the estimated mass transport in a microtiter plate sealed with this dressing is about 5 times slower than that of an unsealed 96 well plate. The aim of this publication is to enable the reader to choose a microtiter plate sealing from the materials evaluated within this work and to use the rapid methods described herein to easily perform tests of additional sealing materials.

Fed-batch operation of an industrial cell culture process in shaken microwells

“…Methods to further reduce evaporation rates, in the microwells would be advantageous in removing the need for use of diluted feeds. The use of thicker or less permeable sealing films, however, would likely result in a reduction in gas-liquid mass transfer rates (Zimmermann et al 2003).…”

A Pitfall of the 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethonyphenol)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) Assay due to Evaporation in wells on the Edge of a 96 well Plate

“…There were no significant differences (p = 0.77) in the cell numbers between the rows, confirming that there was no difference in growth between inner and outer rows. Next, we speculated that the increases in absorbency of the outer wells was due to increased concentration of formazan salt due to evaporation (even though the cells were cultured in a well humidified incubator), as evaporation has previously been documented to be a problem in 96 well plates (Hermann et al 2003, Zimmermann et al 2003. To substantiate this, we measured the volume of media in each well at the end of culture, by weighing the media aspirated.…”

Microwell engineering characterization for mammalian cell culture process development

“…The volumetric oxygen mass transfer coefficient (k L a) was calculated for uncovered wells using the correlation of Doig et al (2005) and then corrected for the added transfer resistance of the breath-easy membrane used to cover the wells as described earlier. Zimmermann et al (2003) have also noted the impact of various microplate sealing membranes on oxygen transfer rate in shaken microwell plates. The predicted k L a values obtained here for 24-SRW plates are summarized in Table II.…”