Tiêu đề 7. MAINTENANCE OF LAB CULTURES.pdf ✅

PHARMD GURU Page 3 This results in dehydration of bacteria with a minimum of damage to delicate cell structures (Fig. 3.8). The vials are then sealed off under a vacuum and stored in a refrigerator. This method has many advantages: a) Cultures preserved by freeze drying method have remained viable for more than 30 years. b) Sub-culturing is not required and the culture can be maintained without contamination. c) The lyophilized strain remains genetically stable. d) Minimal storage space is required. Many lyophilized cultures can be stored in a small area. e) The small vials can be easily sent to other microbiology laboratories through the mail. f) Lyophilized cultures are easily revived by opening of vials and transferring of the rehyderated culture to a suitable growth medium. g) This method is also employed for the preservation of sera, toxins, enzymes and other biologicals.