Hualan Biological Engineering Chongqing Co., Ltd.

Purpose: To find a method to prepare a bacterial suspension containing a specific number of viable bacteria to provide a basis for the accuracy of the test results.Method: The turbidimeter method was used to prepare the concentrated bacteria solution with standard turbidity, and then the viable bacteria were counted on the plate after gradient dilutionResult: Under Number 1 McDonald's turbidity, the suspension of Pseudomonas aeruginosa and Escherichia coli was diluted to 10∼(-7), and the suspension of Staphylococcus aureus was diluted to 10∼(-6) and then 3 mL of bacterial solution+ 7 mL diluted solution, Bacillus subtilis suspension, Clostridium sporogenes suspension diluted to 10∼(-6), Candida albicans suspension diluted to 10∼(-5), 3 mL bacterial solution + 7 mL diluted solution, Aspergillus niger spore suspension diluted After 10∼(-4), 3 mL bacterial solution + 7 mL diluent, the number of viable bacteria is less than 100 cfu.Conclusion: Under the same specific turbidity, the dilution gradient of different test bacteria is very different.The smaller the test bacteria, the larger the dilution gradient.

Acute toxicity of blood-coagulation factor VIII was studied.Human blood-coagulation factor VIII max concentration was 64 IU/mL.Injecting twice a day, 3200 IU/kg, eating, drinking, activity, body weight and death of 20 mice had no disease.Maximum tolerated dose of blood-coagulation factor VIII was 3200 IU/kg, which was safe.