CPC C12P 21/00 (2013.01) [C07K 14/435 (2013.01); C07K 14/43504 (2013.01); C07K 14/70592 (2013.01); C07K 14/70596 (2013.01); C12N 5/0087 (2013.01); C12N 5/10 (2013.01); C12N 15/85 (2013.01); G01N 15/14 (2013.01); G01N 2015/149 (2013.01)] | 21 Claims |
1. A method of producing a population of producer cells expressing a target polypeptide, the method comprising:
(a) transfecting host cells with a vector that encodes one or more mRNAs, wherein the one or more mRNAs encode a selectable polypeptide and the target polypeptide;
(b) isolating from the transfected host cells, between two and four days after transfection, a highly positive transient expression sub-population of early-expressing transfected host cells which express the selectable polypeptide, wherein the highly positive transient sub-population of early-expressing transfected host cells comprises about the top 10 percent of transfected host cells in terms of their expression of the selectable polypeptide; and
(c) expanding the isolated highly positive transient expression sub-population of early-expressing transfected host cells, thereby producing a population of producer cells expressing the target polypeptide, wherein steps (b) and (c) are each performed in drug-selection-free medium.
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