High-throughput Biopolymer Desalting Prior to Mass Spectrometry
Abstract: Mass spectrometry is a prime method for analysis of
proteins or DNA genetic information. Biopolymer samples are
enzymatically or chemically fragmented, and analyzed by MALDI-TOF MS or
ESI MS. Due to the ion suppression and ion adduct formation it is
mandatory to remove salts from biopolymer samples prior to MS analysis.
We have developed a fast and efficient method to desalt DNA
oligonucleotides and peptides using a 96-well extraction plate packed
with 5 mg of Oasis® HLB sorbent. The polymeric reversed-phase sorbent
strongly retains the biopolymer analytes, while small inorganic ions
are unretained and can be washed out with pure deionized water. DNA
oligonucleotides or peptides are eluted using a small amount (20-150
ul) of acetonitrile-water (70/30, v/v) solution. The biopolymer sample
purification method should be suitable for MS applications such as
protein identification and DNA genotyping.