Cell Topography Correction in Colocalization Analysis
Typ
Examensarbete för masterexamen
Program
Biomedical engineering (MPBME), MSc
Publicerad
2022
Författare
Almehed, Sara
Modellbyggare
Tidskriftstitel
ISSN
Volymtitel
Utgivare
Sammanfattning
Colocalization analysis is the study of the distributions of species with fluorescence microscopy.
By estimating the spatial distribution of the fluoresence emission from two types
of molecules, colocalization analysis is used as a method to help in the understanding of
processes and interactions between molecules both within cells and with their environment.
One of the basic assumptions of colocalization analysis today is that the species of
interest are spatially distributed on a uniform surface, their only interaction being with
each other. The assumption of a uniform surface however, does not always hold. The
plasma membrane for example, is not flat but can be convoluted, folded and deformed in
a large number of ways, causing the assumption of a flat surface to not be applicable when
studying molecules present in the membrane of a cell.
With aim to improve the result of colocalization analysis, we present a method of intensity
normalization by weighting the observed intensities of the species of interest by
the membrane distribution. To study the effect of background normalization on colocalization
analysis, simulations were conducted on non-uniform surfaces where the Pearson
correlation coefficient and Spearman rank correlation coefficient were used to estimate the
amount of colocalization before and after background normalization.
Based on the simulations, together with results from analysis of experimental images
using confocal laser scanning microscopy, we present a proof of concept for the effect of
background normalization on colocalization analysis.
Beskrivning
Ämne/nyckelord
Colocalization analysis , T-cell , correlation , confocal laser scanning microscopy , Gaussian process regression , point processes