Navigation Links
New buffer resists pH change, even as temperature drops
Date:1/14/2008

Researchers at the University of Illinois have found a simple solution to a problem that has plagued scientists for decades: the tendency of chemical buffers used to maintain the pH of laboratory samples to lose their efficacy as the samples are cooled. The research team, headed by chemistry professor Yi Lu, developed a method to formulate a buffer that maintains a desired pH at a range of low temperatures.

The study appears this month in Chemical Communications.

Scientists have known since the 1930s that the pH of chemical buffers that are used to maintain the pH of lab samples can change as those samples are cooled, with some buffers raising and others lowering pH in the cooling process.

Freezing is a standard method for extending the shelf life of biological specimens and pharmaceuticals, and biological samples are routinely cooled to slow chemical reactions in some experiments. Even tiny changes in the acidity or alkalinity of a sample can influence its properties, Lu said.

We like to freeze proteins, nucleic acids, pharmaceutical drugs and other biomolecules to keep them a long time and to study them more readily under very low temperatures using different spectroscopic techniques and X-ray crystallography, Lu said. But when the pH changes at low temperature, the sample integrity can change.

Graduate student Nathan Sieracki demonstrated this by repeatedly freezing and thawing oxacillin, a penicillin analog used to treat infections.

After one freeze-thaw 50 percent of the drug was dead in several of the buffers investigated, Sieracki said.

Sieracki was able to demonstrate that the loss of activity was due to changes in pH and not a result of the temperature changes.

To find a buffer that would maintain a stable pH at varying temperatures, Sieracki first evaluated the behavior of several commonly used buffers over a range of temperatures. He saw that some buffers became more alkaline at lower temperatures while others grew more acidic.

These observations led to an obvious methodology: Why dont we just mix them together" Sieracki said.

Little by little, he varied the proportions of the combined buffers until he found a formula that exhibited minimal pH changes at a variety of temperatures. Instead of registering changes of 2 or more pH units while cooling, which was typical of some standard buffers, the new formula changed less than 0.2 pH units during cooling, he said.

Were canceling out 100-fold changes in proton concentration and bringing them down within an order of magnitude, Sieracki said.

The creation of a temperature-independent pH (TIP) buffer could have broad implications for new and previously published research, Lu said.

Were not in the business of looking at the literature and correcting other mistakes, he said. But some of the conclusions from previous studies could be on shaky ground if a buffer was used that changed pH dramatically at low temperatures.

The new buffer is immediately useful for biological research, and Sieracki said he is confident that a similar buffer could be made for use in many fields, such as biochemistry, biophysics, chemical biology and biomedical research.


'/>"/>

Contact: Diana Yates
diya@uiuc.edu
217-333-5802
University of Illinois at Urbana-Champaign
Source:Eurekalert  

Related medicine news :

1. Climate change, gender differences, health among EurekAlert! 10 Most Popular Stories in 2007
2. APHA Adopts New Policies on Food Safety, Global Climate Change, Multidrug-Resistant Organisms, Breastfeeding and Feminine Hygiene
3. Summer Temperatures Linger, Extend Threat of Parasites
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
New buffer resists pH change, even as temperature drops
(Date:9/22/2017)... PITTSBURGH, PA (PRWEB) , ... September 22, 2017 ... ... as soon as possible, and they often saves lives. However, if one isn’t ... order to widen the availability of defibrillation, I came up with this idea," ...
(Date:9/22/2017)... ... 22, 2017 , ... After a long health ordeal that ... lease on life with assistance from CreditAssociates. CreditAssociates provides debt relief and debt ... debt. The senior is one of the satisfied clients who expressed their appreciation ...
(Date:9/22/2017)... ... September 22, 2017 , ... Happy Living’s mission - to improve ... carries it into the entertaining and delicious worlds of theatre and wines. , ... Living) convinced him to turn his play into a book. The Greener The Grass ...
(Date:9/22/2017)... ... September 22, 2017 , ... TopConsumerReviews.com ... by Native Remedies that helps promote pancreatic health and regulate blood sugar ... some prescription-based approaches can have negative side effects, and with the changes in ...
(Date:9/22/2017)... ... September 22, 2017 , ... ... brush more effectively even on the go. Their electric toothbrushes aggressively attack oral ... inflammation, with UV sanitizing technology. Combining leading edge Enke technology with a premium ...
Breaking Medicine News(10 mins):
(Date:9/12/2017)... , Sept. 12, 2017  Consumer reviews on the independent ... as the number one company for hearing aids, ranking it ... fifteen other brands. ... Hearing Named #1 by Consumers For Hearing Aids ... Embrace Hearing is an online store that provides high performance, ...
(Date:9/7/2017)... 7, 2017  Eli Lilly and Company (NYSE: ... streamline operations to more efficiently focus resources on ... structure. Global workforce reductions, including those from a ... impact approximately 3,500 positions. With ... savings of approximately $500 million that will begin ...
(Date:9/7/2017)... , Sept. 7, 2017   BioLife Solutions , ... and marketer of proprietary clinical grade cell and tissue ... announces that Mike Rice , President and CEO, will ... Rodman & Renshaw 19 th Annual ... Eastern time (12:25 p.m. Pacific time). The conference is being ...
Breaking Medicine Technology: