Microplate Sealing Film 101: Which Should You Use For Your Samples?

Also known as universal optical microplate sealing tapes, pressure sensitive films are made from high optical-grade materials, making them ideal for real-time PCR (qPCR) or other fluorescence-based systems. This ensures that the laser or light source in your plate reader or thermocycler can penetrate the seal and return to the detector with minimal interference.

As the name implies, these sealing films require pressure to activate the strong adhesive. Once the seal is properly placed on the plate, applying pressure on the perimeter bursts the encapsulated adhesive, causing the tape to bond with the plate's well rims.

One of the most common issues in plate-based assays is the edge effect, in which wells on the plate's perimeter evaporate faster than those in the center. Self-adhesive sealing films, often called polyester microplate sealing tapes, use a uniform adhesive layer that provides an effective well-to-well seal.

Since polyester is chemically inert and durable, PET sealing films are ideal for transporting samples between labs or for a 2-hour room-temperature incubation. They are also ideal for multi-day storage in fluctuating temperatures. 

Foil plate sealing films or aluminum microplate sealing tapes work well with heated lids in thermal cyclers. This eliminates the need for mineral oil in preventing evaporation in PCR and reduces the risk of sample contamination.

Given that aluminum is an effective heat conductor, aluminum foil sealing films are ideal for optimizing thermal transfer across the top of the plate. As a result, the temperature inside the wells and the top air space reaches the target temperature much faster.

Breathable microplate sealing tapes allow for adequate O2 and CO2 exchange, which is essential for aerobic cell cultures where the metabolic rate depends on a constant oxygen supply. Without this exchange, cells may die, and gene expression may be altered.

Although these films allow gas to pass through, their pores act as a sterile barrier. This protects your sensitive cultures from airborne contaminants, bacteria, and mold spores.

Pierceable plate sealing films let you access your samples directly, without the hassle of peeling or removing the seal. By allowing pipette tips or robotic probes to punch through the material, these films lower the risk of cross-contamination and the sudden aerosolization that often occurs when snapping off a standard adhesive.

Using high-quality pierceable sealing films is recommended to avoid sample contamination and needle clogging. Otherwise, seal fragments can be pushed into the sample or lodged inside the pipette tip upon entry.

According to My Green Lab, both constant and variable air velocity fume hoods consume significant amounts of energy. However, variable air velocity fume hoods typically use 110 kWh/day or approximately 3.5 homes' worth of energy per day. 

Fume hoods are among the largest energy drivers in a lab. When you leave the fume hood sash open, exhaust fans pull in significant amounts of heated or cooled conditioned air, which is then released outside. If this cycle is left running continuously with the sash open, it causes a spike in energy use.