Sunday November 11, 2007
The need to separate larger molecules from smaller molecules is a recurring theme in life science research. For example, PCR reactions, restriction digests, ligations, and DNA or RNA labeling reactions all generate nucleic acid products that are, in most cases, larger than the reaction components that could interfere with downstream applications. Similarly, protein solutions frequently require buffer exchange or the removal of unincorporated label, such as biotin or 125I. Fortunately, separating the nucleic acid or protein products of interest from smaller contaminants is a simple matter with size exclusion spin columns. With sample volumes ranging from 10 µl to 0.5 ml, finding a spin column to fit your specific application is never a problem. Size exclusion spin columns come ready to use and are preloaded with a variety of buffers that are optimized for different applications. Some spin columns are recommended only for nucleic acids, some only for proteins, and a few are suitable for both nucleic acids and proteins. Size exclusions range from 10 to 200 bp for nucleic acids and from 6 to 12 kDa for proteins. These are the numbers you’ll want to keep in mind when choosing a spin column so you don’t lose your molecule of interest. Just make sure your nucleic acid or protein is larger than the size exclusion, also called the molecular weight cutoff (MWCO), and you’re all set. Since most size exclusion spin columns on the market today have product recoveries of over 90% and can remove over 95% of contaminating small molecules, you really can’t wrong with a spin column from any of the vendors on the Biocompare pages. Below is a short list of size exclusion spin columns to get you started.
Michael Campa, PhD
Assoc. Research Professor of Radiology
Duke University Medical Center
Note: Biocompare disclaims any information on this site.
Price information is approximate list price and actual prices may vary.