Microwave ovens and guidelines for their usage vary among laboratories. However, the following tips are useful for all technicians using the microwave for special staining procedures:
- Microwave ovens heat solutions unevenly from the inside out. If possible, stirrers should be used while heating solutions. If stirrers are not available, the solution should be pipetted to mix the solution and even out the distribution of heat.
- The temperature of solutions and tissue that are placed in the microwave affects the length of heating time. More time is needed to reach a specific temperature for refrigerated materials than for room temperature materials.
- Never use metal containers because they reflect the microwaves and shield the solutions from heating.
- Containers used in a microwave oven should be open, vented, or loosely covered to prevent pressurization.