2.7.3 Scanning electron microscopy
Cells of S. aureus were prepared as described. Take several cells cultured for 10 h (OD600 = 0.5), remove the culture medium after centrifugation, wash twice with PBS, and discard the supernatant. After precooling, slowly add 2.5% glutaraldehyde fixed solution along the test tube wall and store it at 4 ℃ overnight. The cells were observed using scanning electron microscopy (SEM) (SU8010, Hitachi, Tokyo, Japan) as previously described (Kumari et al., 2019).