Evaluation of infrared QCL, Synchrotron and bench-top sources for cell imaging in aqueous media

UoM administered thesis: Phd

  • Authors:
  • Zhe Zhang

Abstract

Live cell imaging with FTIR spectroscopy offers a high throughput, non-damage and lab-free method to study the cells in vivo which has significant advantages in the field of cancer diagnosis and drug screening. However, due to the strong absorbance of water, using infrared spectroscopy in such field remains to be an underdeveloped topic. This project demonstrates a novel method to perform IR imaging of cells in solution. A novel water correction method, which avoids the using of water combination band, is proposed. A buffer reference and a cell reference spectra were introduced to fitting the contribution based on protein bands. This method was implemented on three types of IR spectrometers, namely conventional FTIR spectrometer, synchrotron-based FTIR spectrometer and quantum cascade laser (QCL) microscope. To date, most of the live cell imaging carried out with IR sources utilise synchrotron radiation. Recently, a new bench top system, QCL microscope, has been developed. It incorporates four tunable QCL laser sources covering the wavenumber range 900-1800 cm-1 which are many orders of magnitude brighter than conventional sources. The proposed water correction method is, therefore, capable of processing the data recorded by all three types of IR spectrometers. Three prostate cancer cell lines were employed to evaluate the water correction method and the performance of three spectrometers on imaging of cell in solution. The obtained spectra was analysed with multivariate analysis, PCA and PC-LDA which shows good separation between cell lines. The data was also examined with Random Forest algorithm to establish a classifier and the diagnostic capability of the water corrected spectra was proven.

Details

Original languageEnglish
Awarding Institution
Supervisors/Advisors
Award date1 Aug 2017