Lab Scale Autoclave

A lab-scale autoclave is a compact, pressure-chamber device specifically designed for steam sterilization in smaller laboratory settings. They are essential for microbiology, research, and quality assurance labs where daily sterilization of small batches of items is necessary.

They are commonly referred to as benchtop or vertical autoclaves, depending on their physical configuration.

Types and Capacity

Lab-scale autoclaves are categorized primarily by their form factor and capacity:

• Benchtop Autoclaves (Tabletop, Front-Loading):
  • These are compact, horizontal units designed to sit directly on a laboratory bench, similar to a large microwave.
  • Capacity: Typically range from 8 liters (L) to 50 L.
  • Loading: Feature a front-opening door, which is convenient for labs with limited vertical space.
• Vertical Autoclaves (Top-Loading):
  • These are cylindrical, upright units that often sit on the floor, though smaller models may be placed on a sturdy bench.
  • Capacity: Generally larger than benchtop models, ranging from around 35 L up to 150 L for mid-sized lab versions.
  • Loading: Feature a hinged lid on top, making them suitable for sterilizing tall items like large flasks and media bottles.

Common Lab Applications

Lab-scale autoclaves use pressurized steam to achieve sterilization at temperatures typically between 121^◦C and 134^◦ C(at a pressure of about 0.12 MPa to 0.22 MPa or 15-32 psi).

They are used to sterilize items that are heat- and moisture-stable, including:

• Culture Media: Preparing sterile growth media (agar, broths) for microbiology and cell culture.
• Glassware: Flasks, beakers, pipettes, test tubes, and other reusable lab vessels.
• Instruments: Metal tools, surgical instruments, and lab equipment.
• Biohazard Waste: Decontaminating used culture plates, samples, and infectious waste before disposal.
• Liquids: Sterilizing buffers, water, and reagents (often requiring specialized cooling or air-ballasting features to prevent boil-over).

Key Features of Modern Lab Autoclaves

Modern units offer advanced controls and features beyond basic pressure cooker models:

• Automated Cycles: Microprocessor-controlled pre-set programs for solids, liquids, and waste sterilization.
• Vacuum Systems (for Class B/S models): A vacuum pump removes air from the chamber before steam is introduced, ensuring complete steam penetration, especially for porous or wrapped loads.
• Temperature Monitoring: Often include flexible PT100 probes to monitor the temperature inside the liquid or load, not just the chamber, which is crucial for liquid cycle safety.
• Fast Cooling: Options like air ballast (compressed air injection) or cooling coils to quickly reduce the temperature of liquid loads, protecting the contents and reducing cycle time.
• Safety Interlocks: Mechanisms that prevent the door from being opened until the pressure inside the chamber has returned to a safe ambient level.