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 , ... Dickinson Insurance and Financial Services, ... preparation services, is providing an update on a charitable event that began earlier ... is a locally recognized nonprofit that provides shelter and care for animals seeking ...
(Date:10/13/2017)... ... October 13, 2017 , ... ... process to promote standards of excellence for the field of eating disorders, announces ... 22 – 25, 2018 in Orlando, Florida at the Omni Resort at ChampionsGate. ...
(Date:10/13/2017)... ... 13, 2017 , ... Apple Rehab Shelton Lakes , which specializes in ... the facility as part of a disaster drill on October 3rd. , Apple Rehab ... City Emergency Manager, as well as the Connecticut Long Term Care Mutual Aid ...
(Date:10/13/2017)... (PRWEB) , ... October 13, 2017 , ... Global Healthcare ... scenic Alexandria Park in Milford, NJ. This free event, sponsored by Global Healthcare ... activity. The fun run is geared towards children of all ages; it is ...
(Date:10/13/2017)... ... ... “The Journey: From the Mountains to the Mission Field”: the story of a missionary ... Journey: From the Mountains to the Mission Field” is the creation of published author, ... ages and currently teaches a class of ladies at her church, which she has ...
Breaking Medicine News(10 mins):
(Date:10/2/2017)... , Oct. 2, 2017  AllianceRx Walgreens Prime, ... formed by Walgreens and pharmacy benefit manager Prime Therapeutics ... new brand, which included the unveiling of new signage ... , as well as at a few other company-owned ... new brand to patients, some of whom will begin ...
(Date:9/28/2017)... Sept. 28, 2017 Cohen Veterans Bioscience and ... use of wearable and home sensors for real-time monitoring ... Signal Foundation, a nonprofit organization focused on disruptive health ... an affordable analytical system to record and integrate behavioral, ... ...
(Date:9/25/2017)... 2017  EpiVax, Inc., a leader in the ... today announced the launch of EpiVax Oncology Inc., ... therapeutic cancer vaccines. EpiVax has provided $500,000 in ... enabling technologies to the new precision immunotherapy venture. ... Oncology as Chief Executive Officer. Gad brings over ...
Breaking Medicine Technology: