US 12,275,953 B2
Methods for screening host cells expressing target proteins
Yen-Ju Lin, Taichung (TW); Mei-Wei Lin, Zhubei (TW); and Min-Yuan Chou, Taipei (TW)
Assigned to INDUSTRIAL TECHNOLOGY RESEARCH INSTITUTE, Hsinchu (TW)
Filed by Industrial Technology Research Institute, Hsinchu (TW)
Filed on Dec. 29, 2021, as Appl. No. 17/564,729.
Claims priority of provisional application 63/131,492, filed on Dec. 29, 2020.
Prior Publication US 2022/0228110 A1, Jul. 21, 2022
Int. Cl. C12N 5/00 (2006.01); C07K 14/47 (2006.01); C12N 15/85 (2006.01); G01N 33/50 (2006.01)
CPC C12N 5/0081 (2013.01) [C07K 14/4717 (2013.01); C12N 15/85 (2013.01); G01N 33/5014 (2013.01)] 10 Claims
 
1. A method for screening and selecting mammalian host cells expressing a target protein, comprising:
(a) providing an expression vector comprising a promoter, a gene encoding a target protein and a Ferritin Heavy Chain 1 (FTH1) gene, wherein the FTH1 gene is used as a selection marker;
(b) transfecting the mammalian host cells with the expression vector;
(c) culturing the transfected mammalian host cells of step (b) in a culture medium;
(d) adding 100 μM to 1.5 mM of iron ions and 0.5 μM to 2 mM of a ferroptosis inducer to the culture medium of step (c); and
(e) screening and selecting the surviving mammalian host cells comprising the expression vector to obtain the mammalian host cells expressing the target protein.