Investigation of the effect of trypsin on cell-detachment using quantitative phase interferometry (QPI) method

• Main Author: Law, Shawn Siang Wei
• Other Authors: Chian Kerm Sin, Sandy
• Format: Final Year Project
• Language: English
• Published: 2019
• Subjects: DRNTU::Engineering::Mechanical engineering
• Online Access: http://hdl.handle.net/10356/77861
• Institution: Nanyang Technological University

The detachment of a cell from a surface is widely studied as many procedures rely on the decellularisation of a tissue. However, the process and method in which each individual cell detaches is yet to be fully examined in detail. By obtaining a clearer understanding of how a cell detaches from the surface, efficiency and efficacy for various decellularisation methods can be improved. Trypsin is a proteolytic enzyme and it is widely utilised in cell detachment from the adherent substrate. Multiple aseptic cell culture techniques rely on the usage of trypsin as part of the procedure due to the tolerance of this enzyme by the cell. Cell transparency presents inadequacy of light microscopy analysis. Hence, Quantitative Phase Interferometry (QPI) method, a laser aided microscopy technique for imaging of semi-transparent samples will be employed to aid in this investigation. This study hopes to investigate the fundamental effects and exposure of trypsin on cell detachment process by quantifying the phase images obtained with QPI over the duration of the detachment. L929 fibroblast cells was subcultured within optimum environmental conditions until a desired confluency was achieved. Light microscopy would be used to obtain the baseline observation of the cell detachment with 0.1% trypsin. Another analysis was conducted using QPI techniques which provided the optical path length (phase) containing information about the cell’s thickness. The phase map produced showed a three-dimensional graphical representation of the cell and its changes which allowed the observation of the detachment process. Results from QPI inspection, displayed that the cell shrank from its elongated profile to tall bell shape structure indicating detachment from substrate. Cell membrane was unaffected by trypsin as there was no leakage of cellular material. QPI’s three dimensional phase mapping actualises the detachment process.