Tyndallization is used at a pharmaceutical factory as a sterilization method for thermolabile substances. Essentially this method consists of:

Answer options

1. Sterilization with flowing steam at 100°C
2. Sterilization with dry heat at 180-200°C for a lengthy period of time
3. Autoclaving at 119-121°C with pressure at 1.0-1.1 atm
4. Sterilization with high-frequency and microwave frequency current
5. Triple heating of solution to 40-60°C with 24-hour-long intervals in between for thermostating