VWR Orbital Microplate Shaker Model 3500

The VWR (Henry Troemner/Talboys) Orbital Microplate Shaker (Model 3500, Catalog 89032-092) is a specialized benchtop instrument designed to provide vigorous, uniform mixing for 96-well, 384-well, and deep-well plates. Unlike general-purpose shakers that use large orbits, this unit features a tight 0.12-inch (3.6 mm) orbital motion. This small orbit is mechanically optimized for microplates; it ensures that liquids are vortexed effectively within the small diameter of the wells without splashing out or wetting the sealing film, which is a common risk with standard 19mm orbit shakers.

The unit is equipped with a non-slip rubber mat and can be used wtih appropriate retention mechanisms to secure up to four standard microplates (or two deep-well blocks) simultaneously, preventing them from rattling or dislodging during high-speed operation. The drive system utilizes a permanently lubricated ball-bearing motor that provides quiet, maintenance-free operation across a speed range typically spanning from 500 to 2500 RPM. This variable speed control allows the user to switch easily between gentle agitation for delicate cell cultures and aggressive vortexing for resuspending difficult pellets.

Built for versatility in various lab environments, the Model 3500 is housed in a heavy-duty cast aluminum base which provides the necessary weight to prevent the unit from "walking" across the benchtop during operation. The internal components are rated for cold room and incubator use (usually from 0°C to 40°C and up to 80% non-condensing humidity), making it suitable for temperature-sensitive assays like ELISA or protein crystallization.

Used; excellent condition; timing function does not count down, however.