ABSTRACT
OBJECTIVE: To establish an in vitro method to determine the biological activity of Pseudomonas aeruginosa injection as an alternative to current animal tumor inhibition experiments. METHODS: With its significant immunogenicity and mitogenicity, PA-MSHA strain, the active ingredient of Pseudomonas aeruginosa injection, was directly added to and incubated with spleen cells isolated from BALB/c mice in vitro. MTT assay was conducted to assess the cell proliferation effect of PA-MSHA, and the stimulate index (SI) was used as an indicator to evaluate the biologic activity. The complete experiment system was explored by optimizing test conditions, then ten batches of Pseudomonas aeruginosa injection were tested for three times. RESULTS: When the dilution ratio of Pseudomonas aeruginosa injection was 1:200, all of the SIs were greater than 2.0, and the inter-batch coefficient of variations were 0.039-0.052. CONCLUSION: This method not only has good stability and high accuracy, but also saves the cost and time remarkably. Through the statistical analysis of test data, the preliminary eligible criteria of the biological activity of Pseudomonas aeruginosa injection were also established.