title: A simple peak detection and label-free quantitation algorithm for chromatography-mass spectrometry.
abstract: BACKGROUND
  Label-free quantitation of mass spectrometric data is one of the simplest and least expensive methods for differential expression profiling of proteins and metabolites. The need for high accuracy and performance computational label-free quantitation methods is still high in the biomarker and drug discovery research field. However, recent most advanced types of LC-MS generate huge amounts of analytical data with high scan speed, high accuracy and resolution, which is often impossible to interpret manually. Moreover, there are still issues to be improved for recent label-free methods, such as how to reduce false positive/negatives of the candidate peaks, how to expand scalability and how to enhance and automate data processing. AB3D (A simple label-free quantitation algorithm for Biomarker Discovery in Diagnostics and Drug discovery using LC-MS) has addressed these issues and has the capability to perform label-free quantitation using MS1 for proteomics study.
  
  
  RESULTS
  We developed an algorithm called AB3D, a label free peak detection and quantitative algorithm using MS1 spectral data. To test our algorithm, practical applications of AB3D for LC-MS data sets were evaluated using 3 datasets. Comparisons were then carried out between widely used software tools such as MZmine 2, MSight, SuperHirn, OpenMS and our algorithm AB3D, using the same LC-MS datasets. All quantitative results were confirmed manually, and we found that AB3D could properly identify and quantify known peptides with fewer false positives and false negatives compared to four other existing software tools using either the standard peptide mixture or the real complex biological samples of Bartonella quintana (strain JK31). Moreover, AB3D showed the best reliability by comparing the variability between two technical replicates using a complex peptide mixture of HeLa and BSA samples. For performance, the AB3D algorithm is about 1.2 - 15 times faster than the four other existing software tools.
  
  
  CONCLUSIONS
  AB3D is a simple and fast algorithm for label-free quantitation using MS1 mass spectrometry data for large scale LC-MS data analysis with higher true positive and reasonable false positive rates. Furthermore, AB3D demonstrated the best reproducibility and is about 1.2- 15 times faster than those of existing 4 software tools.
authors.affiliation: Eisai Co., Ltd., Tsukuba, Ibaraki, 300-2635, Japan. k3-aoshima@hhc.eisai.co.jp.
authors.forename: Ken
authors.initials: K
authors.lastname: Aoshima
authors.affiliation: Eisai Co., Ltd., Tsukuba, Ibaraki, 300-2635, Japan. k20-takahashi@hhc.eisai.co.jp.
authors.forename: Kentaro
authors.initials: K
authors.lastname: Takahashi
authors.affiliation: iBio Tech Co., Ltd., Tsukuba, Ibaraki, 305-0031, Japan. m_ikawa@ibio-tech.com.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Ikawa
authors.affiliation: Eisai Co., Ltd., Tsukuba, Ibaraki, 300-2635, Japan. t4-kimura@hhc.eisai.co.jp.
authors.forename: Takayuki
authors.initials: T
authors.lastname: Kimura
authors.affiliation: iBio Tech Co., Ltd., Tsukuba, Ibaraki, 305-0031, Japan. m_fukuda@ibio-tech.com.
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Fukuda
authors.affiliation: Shimadzu Corporation, Kyoto, 604-8511, Japan. satstnka@shimadzu.co.jp.
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tanaka
authors.affiliation: Shimadzu Corporation, Kyoto, 604-8511, Japan. howell.parry@thermofisher.com.
authors.forename: Howell E
authors.initials: HE
authors.lastname: Parry
authors.affiliation: Shimadzu Corporation, Kyoto, 604-8511, Japan. yfujita@shimadzu.co.jp.
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Fujita
authors.affiliation: Shimadzu Corporation, Kyoto, 604-8511, Japan. acyshzw@shimadzu.co.jp.
authors.forename: Akiyasu C
authors.initials: AC
authors.lastname: Yoshizawa
authors.affiliation: Shimadzu Corporation, Kyoto, 604-8511, Japan. utu@shimadzu.co.jp.
authors.forename: Shin-Ichi
authors.initials: S
authors.lastname: Utsunomiya
authors.affiliation: Shimadzu Corporation, Kyoto, 604-8511, Japan. kajihara@shimadzu.co.jp.
authors.forename: Shigeki
authors.initials: S
authors.lastname: Kajihara
authors.affiliation: Shimadzu Corporation, Kyoto, 604-8511, Japan. koichi-t@shimadzu.co.jp.
authors.forename: Koichi
authors.initials: K
authors.lastname: Tanaka
authors.affiliation: Eisai Co., Ltd., Tsukuba, Ibaraki, 300-2635, Japan. y-oda@hhc.eisai.co.jp.
authors.forename: Yoshiya
authors.initials: Y
authors.lastname: Oda
mesh_terms: D000465:Algorithms; D000818:Animals; D002417:Cattle; D002853:Chromatography, Liquid / Q000379:methods*; D030562:Databases, Protein; D006367:HeLa Cells; D006801:Humans; D013058:Mass Spectrometry / Q000379:methods*; D010446:Peptide Fragments / Q000032:analysis*; D011506:Proteins / Q000032:analysis*; D020543:Proteome / Q000032:analysis*; D040901:Proteomics / Q000379:methods; D012710:Serum Albumin, Bovine / Q000032:analysis; D012984:Software
chemical_list: D010446:Peptide Fragments; D011506:Proteins; D020543:Proteome; D012710:Serum Albumin, Bovine