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CHOZN® GS-/- ZFN-modified CHO cell line

CHOZN® ZFN-Modified CHO Cell Lines


CHOZN® GS-/- ZFN-modified CHO cell line
glutamine synthetase knockout cell line


DMSO: 5 mg/mL, clear

shipped in

liquid nitrogen

storage temp.


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General description

ZFNs are a class of engineered DNA-binding proteins and causes a double-strand break. This double-strand break is necessary for site-specific mutagenesis mediated DNA repair. It facilitates targeted genome editing by binding to a user-specified locus. Glutamine synthetase (GS) is one of the most commonly used selectable markers in the biopharmaceutical industry. Glutamine is an essential amino acid for cellular growth. The GS enzyme is responsible for the conversion of glutamate into glutamine. Without this enzymatic activity, cells can no longer synthesize glutamine endogenously and if glutamine is not supplemented in the culture media, the cells will die.
CHOZN cell lines were created utilizing Sigma′s proprietary CompoZr Zinc Finger Nuclease (ZFN) technology to create genetic modifications in parental CHO-K1 cells. Cells are banked in chemically defined, animal component free EX-CELL CD CHO Fusion media

Cell Line Origin

CHOZN cell lines are all subclones of the parental CHO-K1 cell line originated by Puck in 1957.


This product is shipped in liquid nitrogen dry vapor shippers.
Liquid nitrogen dry vapor shipper fee (up to a maximum of $125) and freight not included in price of product.
Liquid nitrogen dry vapor shipper is not disposable and should be returned after receipt. A $450 liquid nitrogen dry vapor shipper fee will be charged if not returned within 1 week of delivery.
Learn more about liquid nitrogen dry vapor shipper

Physical form

CHOZN cell lines are provided to customers in vials containing >7.5e6 cells/mL

Legal Information

All CHOZN cell lines are sold under license from Sigma Aldrich. A copy of the research license is provided with purchase of the CHOZN cell lines.
CHOZN is a registered trademark of Sigma-Aldrich Co. LLC

Storage Class Code

10 - Combustible liquids

WGK Germany


Flash Point F

Not applicable

Flash Point C

Not applicable

Certificate of Analysis

Certificate of Origin

Cytotoxic effects during knock out of multiple porcine endogenous retrovirus (PERV) sequences in the pig genome by zinc finger nucleases (ZFN).
Semaan M, et al.
PLoS ONE, 10(4), e0122059-e0122059 (2015)
The metabolic profile of tumors depends on both the responsible genetic lesion and tissue type.
Yuneva M O, et al.
Cell Metabolism, 15(2), 157-170 (2012)
Q's next: the diverse functions of glutamine in metabolism, cell biology and cancer.
DeBerardinis R J and Cheng T
Oncogene, 29(3), 313-313 (2010)


Preparing CHO Cells for Higher Productivity by Optimizing a Perfused Seed Train

This application note describes the benefits and performance of Cellvento® 4CHO-X Expansion Medium designed for multiple cell expansion steps from vial thaw to N-1 stages to generate higher biomass for inoculating fed-batch production bioreactors

Selection Process Development in a GS Knock-Out CHO Host Cell Line: The Effects of MSX Addition on Clones Generated in an MSX-Free Process

The Glutamine Synthetase (GS) expression system does not typically require multiple rounds of amplification to isolate high-producing clones (Brown, 1992).

Using Microarray Technology to Select Housekeeping Genes in Chinese Hamster Ovary Cells

In the present study, we have identifi ed species-specifi c housekeeping genes (HKGs) for Chinese Hamster Ovary (CHO) cells using data from microarray gene expression profiling.

Mgat4 May Play a Role in Increased Sialylation by Overexpressing Functional MGAT1 in Mgat1-Disrupted Chinese Hamster Ovary (CHO) Cells

MGAT1 adds N-acetylglucosamine to the Man5GlcNAc2 (Man5) structure. Goh et al. reported increased sialylation after restoring MGAT1 function in MGAT1 deficient CHO cells.

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