Partial least square analysis of lysozyme near-infrared spectra.
Proteins possess strong absorption features in the combination range (5000-4000 cm(-1)) of the near infrared (NIR) spectrum. These features can be used for quantitative analysis. Partial least squares (PLS) regression was used to analyze NIR spectra of lysozyme with the leave-one-out, full cross-validation method. A strategy for spectral range optimization with cross-validation PLS calibration was presented. A five-factor PLS model based on the spectral range between 4720 and 4540 cm(-1) provided the best calibration model for lysozyme in aqueous solutions. For 47 samples ranging from 0.01 to 10 mg/mL, the root mean square error of prediction was 0.076 mg/mL. This result was compared with values reported in the literature for protein measurements by NIR absorption spectroscopy in human serum and animal cell culture supernatants.
Hu
S Y
SY
Department of Chemistry University of Iowa, Iowa City 52242, USA.
Lillquist
A
A
Arnold
M A
MA
Wiencek
J M
JM
D000818:Animals; D002138:Calibration; D002645:Chickens; D004531:Eggs; D005583:Fourier Analysis; D016018:Least-Squares Analysis; D015233:Models, Statistical; D009113:Muramidase / Q000737:chemistry*; D012680:Sensitivity and Specificity; D019265:Spectroscopy, Near-Infrared / Q000379:methods*
D009113:Muramidase