Opsonizing bacteria with Fc fusion proteins

Bacteria are stained with CFSE and resuspended in PBS. 0.3 bacteria (OD 550) are incubated with either 0.05 mg of purified fusion proteins of 1ml of the unpurified fusion protein for 1 h under rotation at 4°C. As a positive control bacteria are incubated with 500 µl of anti-gonococcal sera (heat-inactivated for 1 h at 56°C) and 500 µl PBS. As a negative control bacteria are incubated with 1 ml of PBS. After the incubation the bacteria are washed and resuspended in 1 ml PBS + 2 µl anti-FC antibody for 30 min at 4°C under rotation. Before infection, bacteria are washed once more with PBS.