BioTek technologies: 4-Zone™ Incubation and Condensation Control™

Many BioTek single and multi-mode microplate readers include an incubation function for temperature sensitive applications, such as kinetic assays. Some microplate reader incubators use a heating block with a fan to circulate the hot air and warm the reading chamber and microplate. These forced hot air incubators are effective in heating the chamber but can cause evaporation and edge effects, along with excessive temperature variation across the microplate.

In 1996, BioTek developed a unique and innovative incubator design, that relies on natural convection to heat the reading chamber. The reading chamber in BioTek’s detection systems is constructed of anodized aluminum, an excellent heat conductor. In the reading chamber the microplate is positioned close to the reading chamber’s top and bottom plates.

There are four heating membranes attached to the aluminum plates, two on top, two on the bottom; these produce a highly uniform heat. Each heating element is controlled independently by a PID (proportional, integral and derivative) controller to accurately control the set point in all four zones. This 4-Zone heating is particularly effective for long-term kinetic measurements where the plate is kept inside the reading chamber.

BioTek’s 4-Zone incubator design

This design has been proven effective and consistent, especially with temperature sensitive assays like endotoxin analysis and other long-term kinetics. The same design has been used in every BioTek microplate reader since its inception.

A recent enhancement to the 4-Zone design allows the user to set a slightly higher temperature in the top heaters than the bottom heaters. This temperate gradient minimizes condensation in lidded plates, providing more consistent results for incubated assays, including long term kinetics. This new feature, known as Condensation Control, is available in several BioTek single and multi-mode readers.