HEK-Blue™ Selection Antibiotics for maintenance of HEK-Blue™ Cells HEK-Blue™ Selection is a solution that combines several selective antibiotics. These antibiotics guarantee the persistent expression of the various transgenes introduced in HEK-Blue™-2, HEK-Blue™ TLR2 and HEK-Blue™ TLR4 cells. HEK-Blue™ Selection is provided as 5 x 2 ml tubes of 250X solution. Product is shipped at room temperature.