title: Ultra-filtration of human serum for improved quantitative analysis of low molecular weight biomarkers using ATR-IR spectroscopy.
abstract: Infrared spectroscopy is a reliable, rapid and cost effective characterisation technique, delivering a molecular finger print of the sample. It is expected that its sensitivity would enable detection of small chemical variations in biological samples associated with disease. ATR-IR is particularly suitable for liquid sample analysis and, although air drying is commonly performed before data collection, just a drop of human serum is enough for screening and early diagnosis. However, the dynamic range of constituent biochemical concentrations in the serum composition remains a limiting factor to the reliability of the technique. Using glucose as a model spike in human serum, it has been demonstrated in the present study that fractionating the serum prior to spectroscopic analysis can considerably improve the precision and accuracy of quantitative models based on the partial least squares regression algorithm. By depleting the abundant high molecular weight proteins, which otherwise dominate the spectral signatures collected, the ability to monitor changes in the concentrations of the low molecular weight constituents is enhanced. The Root Mean Square Error for the Validation set (RMSEV) has been improved by a factor of 5 following human serum processing with an average relative error in the predictive values below 1% being achieved. Moreover, the approach is easily transferable to different bodily fluids, which would support the development of more efficient and suitable clinical protocols for exploration of vibrational spectroscopy based ex vivo diagnostic tools.
authors.affiliation: Université François-Rabelais de Tours, Faculté de Pharmacie, EA 6295 Nanomédicaments et Nanosondes, 31 avenue Monge, 37200 Tours, France. franck.bonnier@univ-tours.fr.
authors.forename: Franck
authors.initials: F
authors.lastname: Bonnier
authors.forename: Hélène
authors.initials: H
authors.lastname: Blasco
authors.forename: Clément
authors.initials: C
authors.lastname: Wasselet
authors.forename: Guillaume
authors.initials: G
authors.lastname: Brachet
authors.forename: Renaud
authors.initials: R
authors.lastname: Respaud
authors.forename: Luis Felipe C S
authors.initials: LF
authors.lastname: Carvalho
authors.forename: Dominique
authors.initials: D
authors.lastname: Bertrand
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Baker
authors.forename: Hugh J
authors.initials: HJ
authors.lastname: Byrne
authors.forename: Igor
authors.initials: I
authors.lastname: Chourpa
mesh_terms: D015415:Biomarkers / Q000097:blood*; D005374:Filtration; D005947:Glucose / Q000032:analysis; D006801:Humans; D016018:Least-Squares Analysis; D008970:Molecular Weight; D015203:Reproducibility of Results; D044967:Serum / Q000737:chemistry*; D013055:Spectrophotometry, Infrared
chemical_list: D015415:Biomarkers; D005947:Glucose