Handling samples in a PCR laboratory requires an environment strictly protected against contamination. Molecular workflows involve target sequence amplification, replication, and testing of minute DNA or RNA concentrations. To safeguard samples from airborne contaminants, aerosol transfer, and cross-contamination, a specialized workstation known as a PCR hood (or PCR workstation) is essential.
What Is a PCR Hood?
A PCR hood is an enclosed enclosure designed specifically to provide a clean, sterile workspace for preparing PCR reactions, mixing master mixes, and handling sensitive nucleic acid templates. Equipped with HEPA (High-Efficiency Particulate Air) filtration and integrated shortwave ultraviolet (UV-C) germicidal lamps, it minimizes the risk of foreign DNA/RNA aerosol ingress that could compromise amplification results.
Primary Functions of a PCR Hood
- Preventing Sample Contamination: HEPA filtration removes 99.97% of airborne particulates down to 0.3 microns, maintaining ISO Class 5 air cleanliness over the working deck.
- Decontaminating Tools and Surfaces: UV-C irradiation (typically 254 nm) cross-links thymine bases in residual DNA contaminants on pipettes, tube racks, and work surfaces, rendering them non-amplifiable.
- Isolating Workflows: Physically separates master mix preparation from template addition and post-amplification analysis areas.
Types of PCR Workstations
PCR enclosures generally fall into two operational categories depending on air circulation design:
- Laminar Flow PCR Hoods: Utilize a motorized blower that forces ambient air through a pre-filter and HEPA filter, directing a continuous stream of particle-free positive-pressure laminar air outward toward the operator. This configuration provides rigorous sample protection.
- Dead-Air PCR Boxes: Enclosed non-ventilated cabinets without active blower airflow. Protection relies on physical enclosure and pre-experimental UV decontamination cycles, suitable for basic preparation where air currents could agitate delicate powders or light aerosols.
Operating Best Practices
- Wipe all interior surfaces with 10% sodium hypochlorite (bleach) followed by 70% ethanol or isopropanol before and after each session.
- Run the UV-C decontamination cycle for 15–30 minutes prior to commencing work, ensuring the protective front sash is closed.
- Never leave active samples, enzymes, or fluorescent reagents inside the cabinet during UV irradiation.
- Store dedicated micropipettes and consumables within the hood to prevent external carriage of contaminants.
Browse our clean air equipment lines on the IBS Product Catalogue or contact our technical support team for validation queries.
