Most contamination in a tissue culture lab is a layout problem before it is a technique problem. A good plan moves material in one direction, from dirty to clean to growing, and never back.
The six zones
- Wash and sterilisation. Glassware washing, autoclaves and the water purification system. This is the dirtiest zone and sits at the start of the flow.
- Media preparation. Balances, pH and EC meters, stirrers and stock storage. Keep it separate from the transfer room.
- Transfer room. Laminar flow cabinets, held at positive pressure relative to neighbouring rooms. The work surface should meet ISO 5 (Class 100) air quality.
- Incubation and growth rooms. Lit shelves at a stable temperature, commonly 25 ± 2 °C, with a photoperiod such as 16 hours light and 8 hours dark for many species.
- Hardening area. Where plantlets leave the vessel; graded humidity and shade, ideally connected to a greenhouse.
- Gowning lobby. People enter through a space where they change and sanitise, so the culture rooms do not receive street air.
Rules that prevent contamination
- Material and people move forward through the zones; clean items never travel back through dirty ones.
- Pressure steps up toward the transfer room, so air leaks outward from clean to less clean.
- Floors, walls and ceilings use smooth, sealed, washable finishes with no open joints.
- Pass-boxes carry items between zones instead of opening doors.
- Air handling is sized for heat from lights and equipment, not only for occupancy.
Utilities decide the plan
Before drawing rooms, calculate electrical load, backup power for the autoclave and growth-room cooling, water quality and drainage. A layout that ignores utilities will be redrawn later, at a higher cost.
Our lab setup service includes zoned drawings, a bill of quantities and specification of every element. Compare the options in types of tissue culture labs.