Glass or Plastic?

Glass versus Plastic

As scientific glassblowers, we recall with trepidation the famous line in the movie "The Graduate" starring young Dustin Hoffman; Mr. McGuire has one word of advice: "plastics". Well.....

We'd be remiss if we didn't bring to your attention some recent research:

"Thousands of scientists could be unwittingly ruining their own experiments merely by using standard plastic lab equipment, according to a new study."

by Daniel Cressey, Published online 6 November 2008 | Nature | doi:10.1038/news.2008.121

He is referencing research done by Dr.Andrew Holt of the University of Alberta.

"BREVIA
Bioactive Contaminants Leach from Disposable Laboratory Plasticware.

Disposable plasticware such as test tubes, pipette tips, and multiwell assay or culture plates are used routinely in most biological research laboratories. Manufacturing of plastics requires the inclusion of numerous chemicals to enhance stability, durability, and performance. Some lubricating (slip) agents, exemplified by oleamide, also occur endogenously in humans and are biologically active, and cationic biocides are included to prevent bacterial colonization of the plastic surface. We demonstrate that these manufacturing agents leach from laboratory plasticware into a standard aqueous buffer, dimethyl sulfoxide, and methanol and can have profound effects on proteins and thus on results from bioassays of protein function. These findings have far-reaching implications for the use of disposable plasticware in biological research."

In addition to oleamide, Dr Holt cites quaternary ammonium biocides as compounds having an affect on the activity of receptors, enzymes, and ion channels. These chemicals are routinely used in the manufacturing of plastics such as polypropylene disposables.

Plastics are finding more uses every day, but traditional stainless and glass reactors continue to be viable, if not preferable. Having devoted our lives and livelihoods to the understanding of glass, we're here to say that the next time you need some labware, reaction vessels, fermentation chambers, electrochemical cells, etc., we have one word of advice for you....

GLASS!

These are small Erlenmeyer flasks which we produced for a biofuels research client who needed to replace the plastic ones (the blue ugly one).

Forty liter multiport glass fermentor

There are other reasons to consider using glass over plastics. Biofuels research is being done in glass, as the desired end product is a strong solvent. One of our customers manufactures a line of equipment for fermentation, and in discussions with his clients has heard that cells generally thrive in glass, more so than in plastics and stainless. He has described problems with scaling-up attributable to the switch in vessel material. That is, results and protocols generated in glass vessels do not translate well to large single use wave bags.