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:10/13/2017)... ... October 13, 2017 , ... PurhealthRX , a leading ... Purzorb™ technology. Applying the Purzorb™process to full spectrum CBD oil will revolutionize the rapidly ... CBD form that can be easily incorporated into liquid products, while reducing costs to ...
(Date:10/13/2017)... LUIS OBISPO, Calif. (PRWEB) , ... October 13, 2017 , ... ... Alzheimer’s or dementia. However, many long-term care insurance companies have a waiver for care ... is the 90-day elimination period, when the family pays for care, is often waived, ...
(Date:10/13/2017)... ... ... Yisrayl Hawkins, Pastor and Overseer at The House of Yahweh, has released ... understood books in the Holy Scriptures, Revelation. The Book of Revelation paints a picture ... Many have tossed it off as mere rubbish, but Yisrayl Hawkins says that is ...
(Date:10/13/2017)... ... October 13, 2017 , ... “America On The Brink”: the Christian history ... The Brink” is the creation of published author, William Nowers. Captain Nowers and ... WWII veteran, he spent thirty years in the Navy. Following his career as ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... the demand of today’s consumer and regulatory authorities worldwide. From Children’s to Adults ... tested to meet the highest standard. , These products are also: Gluten ...
Breaking Medicine News(10 mins):
(Date:9/28/2017)... -- Cohen Veterans Bioscience and Early Signal Foundation announce ... home sensors for real-time monitoring of patients with trauma-related ... organization focused on disruptive health solutions for rare disorders ... to record and integrate behavioral, cognitive, physiological and contextual ... ...
(Date:9/23/2017)... 2017 Janssen Biotech, Inc. (Janssen) announced today ... the U.S. Food and Drug Administration (FDA) for the ... the treatment of moderately to severely active rheumatoid arthritis ... are needed to further evaluate the safety of sirukumab ... "We are ...
(Date:9/18/2017)... KALAMAZOO, Mich. , Sept. 18, 2017 /PRNewswire/ ... and OptiMed Specialty Pharmacy of Kalamazoo, Mich. ... a strategic hub service that expedites and streamlines patient ... spirometer, Spiro PD 2.0, and wellness management services.  ... a medical device used to measure lung function for ...
Breaking Medicine Technology: