Cell Xpress™ Cell Line Optimization Service Using Laser-Enabled Analysis and Processing (LEAP™) Technology Angela M. Davis, Genova A. Richardson, Nan Lin, Jennifer R. Cresswell, Matthew V. Caple and Kevin J. Kayser

Cell Sciences and Development, SAFC Biosciences 2909 Laclede Avenue, Saint Louis, MO 63103, USA

047070078

Introduction to Cell Xpress

SAFC Biosciences (SAFCB) Cell Xpress technology combines in situ imaging with laser manipulation to identify, select, and monitor expansion of high recombinant protein secreting clones. Cell Xpress provides signifi cant advantages over microscope-based platforms with respect to throughput, robustness, and automation. Cell Xpress enables rapid analysis of relative secretion heterogeneity and purifi cation of transfected or clonal populations. The Cell Xpress technology, when combined with SAFCB medium, feed, and process optimization, can result in a signifi cant increase in productivity from cell culture-based processes. SAFCB uses this integrated process development platform to develop media and feed for use in the production of a cell culture-derived therapeutic protein from our customers. SAFCB employs Cell Xpress to analyze secretion heterogeneity of an initial cell population which may be either a clonal cell line or a transfected pool. The initial population is laser processed to enrich the population for high producing cells by eliminating low or non-producing cells in the population. Following two to three rounds of enrichment, single cell clones are generated from the enriched pool. Clones and enriched populations are then expanded and screened for growth and productivity performance.

The LEAP Instrument

The LEAP Instrument and the Proprietary C-lect™ 384-Well Plate

Methods

Method Comparison: Cell Xpress vs. Traditional Cell Line Generation

Allows for a more cost-effective and efficient process

More cells from initial population evaluated

Labor -intensive expansion efforts focused on higher producers

Cell Xpress Cell Line Generation

Secretion Assay

Cloning

Expansion

Traditional Cell Line Generation

Cloning

Expansion

Secretion Assay

Secretion Assay

Cloning

Expansion

Cloning

Expansion

Secretion Assay

Cell Xpress combines in situ analysis of individual cell secretion with laser-mediated elimination of poorly-secreting cells

Applications

Laser Enrichment of A Transfected “Pool” Population

Transfected Pool Cell Xpress Enriched Transfected Pool

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Transfected Pool Cell Xpress Enriched Transfected Pool

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Normalized Secretion Area Average Intensity (Binned) Normalized Secretion Area Average Intensity (Binned)

Single Cell Clone Characterization and Selection

Correlation of Maximum Volumetric Productivity vs. Normalized Secretion Area Average Intensity

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Normalized Secretion

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Normalized Secretion

The Benefi ts of Cell Xpress

• Cell Xpress yields higher secreting cell lines faster

– Process 30,000+ clones per single plate

– In situ verifi cation of protein secretion prior to labor-intensive clone expansion efforts

• Provides visual documentation of clones

– Image-based validation of clonality and automated tracking of clonal outgrowth

– Documentation package

Acknowledgements

Erika Holroyd, Kathy Roeder

Schematic Illustration: Cell XpressCapture and Detection

In situ detection of secreted recombinant IgG: Fluorescent-labeled detection reagent detects secreted rIgG (red); live cells are stained with viable cell stain (green).

Quantitative Measurement of Clone Secretion

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