Register for an account

X

Enter your name and email address below.

Your email address is used to log in and will not be shared or sold. Read our privacy policy.

X

Website access code

Enter your access code into the form field below.

If you are a Zinio, Nook, Kindle, Apple, or Google Play subscriber, you can enter your website access code to gain subscriber access. Your website access code is located in the upper right corner of the Table of Contents page of your digital edition.

Planet Earth

A Better Way to Grow Cells

A 120-year-old mystery that's stumped microbiologists has been solved. 

By Lacy SchleyAugust 27, 2015 5:00 AM
petri-dish-comparison.jpg
The vast majority of cells die off in agar growth media (left) that has been prepared traditionally by sterilizing the ingredients together. Using the new method, agar prepared with individually sterilized ingredients (right) proves much more hospitable to the cells growing within. | Y. Kamagata et al./Applied Environmental Microbiology/2014 Dec; 80(24): 7659–7666/ American Society for Microbiology

Newsletter

Sign up for our email newsletter for the latest science news

placeholder

For years, a mystery known as “the great plate count anomaly” has plagued microbiologists: Counts of living cells grown on plates in the lab aren’t as high as counts from the original sample, and no one knows why.

To grow these microorganism cultures in the lab, researchers house samples in petri dishes lined with a nourishing gel mixture derived from algae called agar growth media. But despite the nourishment, just 0.1 to 10 percent of cells make it.

petri-dish-comparison.jpg
The vast majority of cells die off in agar growth media (left) that has been prepared traditionally by sterilizing the ingredients together. Using the new method, agar prepared with individually sterilized ingredients (right) proves much more hospitable to the cells growing within. | Y. Kamagata et al./Applied Environmental Microbiology/2014 Dec; 80(24): 7659–7666/ American Society for Microbiology

It turns out the agar is the problem, says microbiologist Yoichi Kamagata at Hokkaido University in Japan. The standard recipes require mixing agar and phosphate solution before sterilizing them via intense heat. But Kamagata and his team realized this sequence creates hydrogen peroxide, which destroys most of the cells. Sterilize the ingredients separately, and voila, a roughly tenfold increase in cell survival rates.

“I was thinking someone else would have done this kind of experiment, as we have 120 years of agar media history,” Kamagata says. “Nonetheless, nobody cared about the media recipe.”

[This article originally appeared in print as "Recipe for Success."]

2 Free Articles Left

Want it all? Get unlimited access when you subscribe.

Subscribe

Already a subscriber? Register or Log In

Want unlimited access?

Subscribe today and save 70%

Subscribe

Already a subscriber? Register or Log In