Cryo-EM Sample Preparation Laboratory
Environmental performance and workflow considerations (pre-decision guidance)
This guide supports early discussions with architects and engineering teams when planning a cryo-electron microscopy
sample preparation laboratory (grid preparation, vitrification, clipping, and cryogen handling).
Scope note: This page concerns the sample preparation lab. Microscope rooms have different requirements and should be specified
with the instrument supplier and your engineers.
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For a printable reference, download the Advisory Memorandum.
1. Room size and layout strategy
Rather than defining a minimum footprint, plan the room around functional zones and safe circulation during peak use. A practical benchmark for a two-instrument preparation workflow is typically 20–25 square metres, depending on safety clearances and storage approach.
Design prompt: test a “two-user” scenario (simultaneous cryogen transfer and grid handling). Many rooms feel adequate until this moment.
2. Temperature control
For grid preparation, stability and user comfort generally matter more than aggressive temperature control. A common target is around 21 degrees Celsius with a modest tolerance. Avoid strong drafts and large day-to-day swings.
3. Relative humidity
Humidity is often the most consequential room parameter for frost risk during cryogenic handling. Many facilities aim for 20–30 percent relative humidity during grid handling; published examples include preparation labs dehumidified to around 20 percent.
State an expectation for return to target after typical door openings and traffic.
Sensor placement should represent the work zone (bench height, away from supply outlets and doors).
Room-average values can look fine while local drafts undermine vitrification and grid handling.
4. Ventilation and safety
Preparation labs routinely handle large volumes of liquid nitrogen and, in many workflows, liquid ethane. Safety measures are core design requirements, not add-ons.
Include ventilation planning, oxygen deficiency monitoring and alarms, and a defined approach for ethane warming and venting or disposal.
5. Dehumidification “boost mode”
Some facilities use timed or manual dehumidification boosts before grid handling. This can work if the room is well sealed, door traffic is controlled, and the system is sized for rapid recovery. Many purpose-built labs prefer stable continuous control for operational simplicity.
Quick checklist for early design discussions
Room zoning and circulation tested under peak use. Humidity target plus recovery expectations. Air supply avoids drafts. Ventilation and oxygen monitoring designed-in. Safe ethane handling approach agreed early. Allow modest headroom for future expansion.