Abstract:

Objective To compare the methods for rescuing the cell line contaminated by bacteria.
Methods Antibiotics or antibiotic combined with macrophage or animal inoculation were used to eliminate the bacteria in laryngeal squamous carcinoma cell line LSC-1. Then cytokeratin(CK AE1/AE3) and DNA ploidy in LSC-1 cells were detected by immunohistochemical and flow cytometer analysis.
Results ① Cefoperazone/Sulbactam at a dose of 32 mg/L was the best one in three sensitive antibiotics and made LSC-1 cells to survive three passages. Cefoperazone/Sulbactam combined with macrophage made LSC-1 cells to survive 5~6 passages. But in the two methods, bacteria appeared again when Cefoperazone/Sulbactam was eliminated and the cells gradually died. LSC-1 cells that experienced animal inoculation survived over 8 passages with well growth, and bacterial culture was negative. ② The positive rate of CK AE1/AE3 in the cells undergone animal inoculation was higher than that of the other two groups and the same as that of the third passage of LSC-1 largely. ③ DNA ploidy analysis showed that LSC-1 cells undergone animal inoculation had diploid and aneuploid karyotypes and were consistent with the third passage of LSC-1. However LSC-1 treated with Cefoperazone/Sulbactam only expressed diploid.
Conclusion Using animal inoculation to eliminate contaminating bacteria in cell line is a useful method. Not only the bacteria can be cleared thoroughly but also the original characteristics and malignancy of the cell may be reserved.

Key words: adherent cell lines, contamination, rescue