Download or read book Assessment of Tandem Mass Spectra Quality to Improve Protein Identification written by Christian Earl Henry Beaudrie and published by . This book was released on 2006 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Protein identification via tandem mass spectrometry and database searching has become a powerful tool in high-throughput proteomics. However, many tandem mass spectra are noisy, are formed by poorly fragmented peptides, and do not result in peptide assignment. Furthermore, many 'high-quality' un-assigned spectra are discarded as noise when they contain sufficient information for an assignment. A novel method was developed to assess the quality of tandem mass spectra from a LC-QTOF instrument using multivariate classification techniques. Six mass spectral features were first evaluated for their ability to discriminate between 'low-' and 'high-quality' spectra. Next, features were used in combination with three classification methods to create an optimal discriminator. Individual spectra quality scores were determined for two datasets, allowing for the removal of 'low quality' spectra, and a focused database search on 'high quality' unassigned spectra. Using these methods it was possible to reduce data size by 43.2% with a loss of only 5% of 'high-quality' spectra, while increasing peptide identifications by over 6%." --