Development of a semi-automated high throughput transient transfection system.
Transient transfection of mammalian cells provides a rapid method of producing protein for research purposes. Combining the transient transfection protein expression system with new automation technologies developed for the biotechnology industry would enable a high throughput protein production platform that could be utilized to generate a variety of different proteins in a short amount of time. These proteins could be used for an assortment of studies including proof of concept, antibody development, and biological structure and function. Here we describe such a platform: a semi-automated process for PEI-mediated transient protein production in tubespins at a throughput of 96 transfections at a time using a Biomek FX(P) liquid handling system. In one batch, 96 different proteins can be produced in milligram amounts by PEI transfection of HEK293 cells cultured in 50 mL tubespins. Methods were developed for the liquid handling system to automate the different processes associated with transient transfections such as initial cell seeding, DNA:PEI complex activation and DNA:PEI complex addition to the cells. Increasing DNA:PEI complex incubation time resulted in lower protein expression. To minimize protein production variability, the methods were further optimized to achieve consistent cell seeding, control the DNA:PEI incubation time and prevent cross-contamination among different tubespins. This semi-automated transfection process was applied to express 520 variants of a human IgG1 (hu IgG1) antibody.
Department of Early Stage Cell Culture, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
Aaron B
AB
Bos
Department of Early Stage Cell Culture, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
Joseph N
JN
Duque
Department of Molecular Oncology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
Sunil
S
Bhakta
Department of Antibody Engineering, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
Farzam
F
Farahi
Department of Late Stage Cell Culture, Genentech Inc., 1 DNA Way, South San Francisco CA 94080, USA.
Lindsay A
LA
Chirdon
Department of Molecular Oncology, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA.
Jagath R
JR
Junutula
Department of Late Stage Cell Culture, Genentech Inc., 1 DNA Way, South San Francisco CA 94080, USA.
Peter D
PD
Harms
Department of Early Stage Cell Culture, Genentech Inc., 1 DNA Way, South San Francisco, CA 94080, USA. Electronic address: wong.athena@gene.com.
Athena W
AW
Wong
D057205:Automation, Laboratory; D004247:DNA / Q000737:chemistry; D057809:HEK293 Cells; D057166:High-Throughput Screening Assays / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D007097:Imines / Q000737:chemistry; D007074:Immunoglobulin G / Q000032:analysis / Q000737:chemistry; D011095:Polyethylenes / Q000737:chemistry; D012371:Robotics; D014162:Transfection / Q000295:instrumentation* / Q000379:methods*
D007097:Imines; D007074:Immunoglobulin G; D011095:Polyethylenes; C505405:poly(ethylene imine); D004247:DNA
Automation; HEK293T; Protein expression; Transient transfection; Tubespins