title: Surface Adsorbed Antibody Characterization Using ToF-SIMS with Principal Component Analysis and Artificial Neural Networks.
abstract: Artificial neural networks (ANNs) form a class of powerful multivariate analysis techniques, yet their routine use in the surface analysis community is limited. Principal component analysis (PCA) is more commonly employed to reduce the dimensionality of large data sets and highlight key characteristics. Herein, we discuss the strengths and weaknesses of PCA and ANNs as methods for investigation and interpretation of a complex multivariate sample set. Using time-of-flight secondary ion mass spectrometry (ToF-SIMS) we acquired spectra from an antibody and its proteolysis fragments with three primary-ion sources to obtain a panel of 72 spectra and a characteristic peak list of 775 fragment ions. We describe the use of ANNs as a means to interpret the ToF-SIMS spectral data, highlight the optimal neural network design and computational parameters, and discuss the technique limitations. Further, employing Bi3(+) as the primary-ion source, ANNs can accurately classify antibody fragments from the parent antibody based on ToF-SIMS spectra.
authors: Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia.|CSIRO Manufacturing , Clayton, VIC 3168, Australia.
authors: Nicholas G
authors: NG
authors: Welch
authors: Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia.|CSIRO Manufacturing , Clayton, VIC 3168, Australia.
authors: Robert M T
authors: RM
authors: Madiona
authors: Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia.
authors: Thomas B
authors: TB
authors: Payten
authors: Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia.
authors: Robert T
authors: RT
authors: Jones
authors: Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia.
authors: Narelle
authors: N
authors: Brack
authors: CSIRO Manufacturing , Clayton, VIC 3168, Australia.
authors: Benjamin W
authors: BW
authors: Muir
authors: Centre for Materials and Surface Science and Department of Chemistry and Physics, School of Molecular Sciences, La Trobe University , Melbourne, VIC 3086, Australia.
authors: Paul J
authors: PJ
authors: Pigram
mesh_terms: D000327:Adsorption; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D000906:Antibodies / Q000737:chemistry*; D066246:ErbB Receptors / Q000276:immunology; D006801:Humans; D007128:Immunoglobulin Fragments / Q000737:chemistry; D007074:Immunoglobulin G / Q000737:chemistry; D015999:Multivariate Analysis; D016571:Neural Networks, Computer; D025341:Principal Component Analysis; D018629:Spectrometry, Mass, Secondary Ion / Q000706:statistics & numerical data*
chemical_list: D000596:Amino Acids; D000906:Antibodies; D007128:Immunoglobulin Fragments; D007074:Immunoglobulin G; C512478:EGFR protein, human; D066246:ErbB Receptors