Plastic lab equipment not up to snuff: study

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This article was published 07/11/2008 (6156 days ago), so information in it may no longer be current.

TORONTO — A group of scientists warned Thursday that disposable plastic laboratory equipment — such as test tubes and pipette tips — may exude compounds that can interact with solutions or cells placed in them, leading to wonky results.

“We have found that most of the types of plastic that are typically used to manufacture these disposable items that are used worldwide in laboratories, do leach out compounds which are deliberately included during the plastic manufacturing process to improve the properties of the plastics,” said Andrew Holt, senior author of the report and an assistant professor of pharmacology at the University of Alberta in Edmonton.

“And these do affect at least some of the sorts of assays and experiments that many researchers are doing.”

Holt and colleagues from his university, as well as Acadia University in Wolfville, N.S., and Emory University in Atlanta, Ga., reported their findings in this week’s issue of the journal Science.

They cautioned that researchers shouldn’t assume that lab equipment sold as sterile is also inert.

Holt said the news won’t come as a shock to many scientists, who know from experience that plastic ware — ubiquitous in laboratories — seems to have an unwanted influence on some kinds of experiments.

“If you walk around any life science department in a university in Canada and ask particularly the more senior scientists who’ve been around for awhile, many of them will tell you that they don’t trust plastic or they try not to use certain types of plastics in particular experiments,” he said.

“They’ll give you excuses or reasons like ‘The cells don’t seem to behave like they normally would’ or ‘They don’t respond to drugs like we think they should.”‘

Holt and colleagues saw the effect themselves while trying to figure out how certain human enzymes — proteins that trigger chemical reactions — work at the molecular level. They found results that made no sense and set out to find out what had gone wrong.

They discovered some of the tubes they were using were emitting a chemical that inhibited the enzyme activity they were trying to study. To make matters worse, the amount of chemical being emitted varied from brand to brand, from size to size within brands and even within the same batch of equipment.

“So you couldn’t even go with a single manufacturer or a single line of tubes and know that you were going to be safe,” Holt said.

The chemicals given off are processing agents used during the manufacture of the products.

One prevents the buildup of static on the plastic. Another gives the plastic its smooth finish.

— The Canadian Press

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