Assessment of Chromosomal Size Variation in CHO Cells
P.O. Michel, R. Delgado-Gonzalo, M. Hubert, L. Baldi, D.L. Hacker, M. Unser, F.M. Wurm
Proceedings of the MipTec and BioValley Life Sciences Week (MTBVLS'12), Basel BS, Swiss Confederation, September 24-27, 2012, paper no. P181, pp. 117.
Chinese hamster ovary (CHO) cells are widely used for the production of recombinant proteins. Currently, the pharmaceutical industry relies on stable CHO cell clones for therapeutic protein production. Most of the currently used methods to analyze clonality and stability in recombinant cell lines only take into consideration the cellular phenotype. However, few methods are available to study clonality and genomic stability in recombinant cell populations. Here we present a relatively simple, cost-effective method based on digital image processing to analyze metaphase chromosome length. The method was applied to parental and recombinant CHO cells. Metaphase chromosome spreads were prepared from growth-arrested cells and visualized with a confocal microscope after fluorescence staining. An ImageJ plugin was then used to sort the chromosomes by size. In studies of seven different CHO cell lines (20 metaphase spreads for each cell line), we noticed that the average chromosome number was not homogenous and each cell line had a specific chromosomal length pattern. This pattern can be used to identify the CHO cell lines and to assess the degree of homo- or heterogeneity in clonal populations.
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AUTHOR="Michel, P.O. and Delgado-Gonzalo, R. and Hubert, M. and Baldi,
L. and Hacker, D.L. and Unser, M. and Wurm, F.M.",
TITLE="Assessment of Chromosomal Size Variation in {CHO} Cells ",
BOOKTITLE="Proceedings of the {MipTec} and {BioValley} Life Sciences
Week ({MTBVLS'12})",
YEAR="2012",
editor="",
volume="",
series="",
pages="117",
address="Basel BS, Swiss Confederation",
month="September 24-27,",
organization="",
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note="paper no.\ P181")