Generate Stable CHO Cell Lines
Using the CHOgro® High Yield Expression System, exceptional yields of recombinant protein can be obtained by transient transfection of suspension CHO cells. Though transgene expression ceases for the vast majority of cells within one to two weeks post-transfection, a small fraction of transfected CHO cells continues to stably express the recombinant protein through random chromosomal integration of the transfected gene. In this Tip from the Bench, we share a protocol for generating stable cell lines through selection and expansion of CHO cells which produce high levels of recombinant protein.
Maintain Suspension CHO Cells
Suspension CHO cells have emerged as one of the most important cell lines for protein expression in biomanufacturing for their capacity to grow to high cell density in serum-free medium. Successful cell growth of these popular cells is dependent on several factors, which include media composition, culture format and appropriate cell maintenance. In today’s Tip from the Bench, we share a few tips for keeping your suspension CHO cells in transfection-ready shape!
Adjust Nucleic Acid Labeling Density with Label IT®
Ideal labeling density will depend on the nucleic acid being labeled and the intended downstream application of the labeled nucleic acid. With Label IT® nucleic acid labeling technology, the labeling density can easily be adjusted. In this Tip from the Bench, we discuss two methods for tweaking the labeling density.
Calculate Nucleic Acid Labeling Density
The labeling density for nucleic acids labeled with fluorescent Label IT® dyes can be calculated easily using spectrophotometry. Read this Tip from the Bench to learn how to calculate the base:dye ratio and the pmol of dye/µg nucleic acid.
Choosing a Label IT Kit
Label IT® reagents are available in several formats, which provides researchers with a variety of options for their nucleic acid labeling experiments. In this Tip from the Bench, we cover the difference between the four formats of Label IT® kits and provide guidance on which to choose for a given application.
Media Adaptation for Suspension Cells
The success of an experiment can rely on the type of cell culture media used. In certain cases, you may need to adapt your current cell culture to a new medium. A stepwise process may be necessary to minimize stress and to retain normal cellular phenotype. Check out this Tip from the Bench to learn how to gradually adapt suspension cells to a new media formulation.
Regulate pLIVE® Expression Level
pLIVE® is a vector system designed for long-term expression in the livers of laboratory rodents. In this Tips from the Bench, we share how gene expression levels can be modulated by changing the relative position of the gene of interest within the pLIVE® multiple cloning site. We also discuss testing the pLIVE® construct in vitro before beginning in vivo studies.
Adapt Adherent CHO Cells to Suspension Culture
Chinese Hamster Ovary (CHO) cells are a popular workhorse for production of recombinant therapeutic proteins. Amenable to both adherent and suspension culture, CHO cells offer versatility in growth platform that is favorable to the end user’s requirements.
In this Tips from the Bench, we highlight factors that differentiate adherent and suspension CHO cell cultures. Also, we describe a simple protocol for transitioning adherent CHO cells to suspension growth (and serum-free medium, if required).
Storage of TransITs
Proper storage and handling of TransIT® reagents are required to maintain optimal transfection performance. This is a quick reference page for storage and handling of Mirus TransIT® Transfection Reagents and Kits.
Transfection Troubleshooting Checklist
Having trouble with your transfection experiment? Go through this transfection troubleshooting checklist to eliminate potential transfection problems.