Autoclave Sterilization & Decontamination

Cycle Selection Guide — Interactive Decision Tree

What are you autoclaving?

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▶ Equipment (Dry Items)
Cycle Type
Dry / Gravity
Temperature
121°C
Pressure
15 psi
Time
15–20 min
Items to Autoclave:
  • Tube caps/closures
  • Reusable tools contacting cultures
  • Media bottles (empty)
  • Non-glass, non-pre-sterilized items
Procedure:
  1. Wrap items loosely in aluminum foil or autoclave bags
  2. Apply autoclave tape to each package
  3. Use Dry cycle
  4. Allow to cool completely inside autoclave
  5. Label tape with date and initials
⚠ Safety: Never open autoclave immediately after cycle ends. Wait for pressure to reach 0 psi. Allow items to cool completely.
▶ Liquid Media
≤ 1 L: 20 min
1–2 L: 40 min
All volumes: 121°C, 15 psi
Cycle Type: Liquid (slow exhaust)
Rule of thumb: 20 min per liter
Key Preparation:
  • Fill bottles to no more than 2/3 capacity
  • Loosen caps — never seal tightly
  • Use autoclave-safe glass bottles (borosilicate)
  • Place upright on autoclave tray
Procedure:
  1. Apply autoclave tape
  2. Select Liquid cycle (slow exhaust)
  3. Set time based on volume
  4. When complete, wait for 0 psi
  5. Cool 10–15 min inside autoclave
  6. Tighten caps after cooling to ~60°C
⚠ Safety: Never move or agitate bottles while hot. Superheated media can boil over suddenly. Always loosen caps before autoclaving to prevent bursting.
▶ Solid Waste
Cycle Type
Gravity
Temperature
121°C
Pressure
15 psi
Time
60 min
Items to Decontaminate:
  • Used agar plates
  • Contaminated consumables (tips, tubes)
  • Paper towels/wipes from culture work
  • Disposable swabs & inoculating loops
Procedure:
  1. Place waste in autoclave bag
  2. Fill no more than 3/4 full
  3. Leave bag open (fold loosely)
  4. Place in secondary containment tray
  5. Apply autoclave tape
  6. Use Gravity cycle
  7. Wait for pressure to reach 0 psi
  8. Cool 10–15 min before removing
  9. Seal bag and dispose in regular trash
⚠ Safety: Never seal bags tightly or overfill. Agar plates produce liquid when autoclaved — always use secondary containment to catch runoff. Do NOT autoclave chemical waste, radioactive materials, or sharps.
▶ Liquid Waste
≤ 1 L: 20 min
1–2 L: 40 min
All volumes: 121°C, 15 psi
Cycle Type: Liquid (slow exhaust)
Rule of thumb: 20 min per liter
Types of Liquid Waste:
  • Spent liquid culture media
  • Liquid culture waste from flasks/tubes
  • Rinse water from culture vessels
Procedure:
  1. Collect in autoclave-safe glass bottles/flasks
  2. Fill to no more than 2/3 capacity
  3. Loosen caps — do not seal tightly
  4. Place upright on autoclave tray
  5. Apply autoclave tape
  6. Use Liquid cycle (slow exhaust)
  7. Wait for 0 psi after cycle completes
  8. Cool 15–20 min inside autoclave — do not agitate
  9. Once cool, liquid can be poured down drain
⚠ Safety: Never seal bottles tightly or exceed 2/3 fill. Do not agitate bottles during cooling — superheated liquid can boil over. Check local regulations before draining.

Protocol: 260317_autoclave.md | Updated: 2026-03-17

This interactive diagram is a quick reference. Always consult the full protocol for detailed procedures.