Microplate and Aseptic Vial Freeze-Drying Unit

This freeze-drying device was developed specifically to meet a need that arose from one of our contract research projects. In this project we needed to develop a method of lyophilizing bacteria in screw capped tubes in batch and aseptically. Though this task at first didn’t appear difficult, we soon realized that no easy, cost-effective method existed for this process. Thus we designed, built, and tested this freeze-drying unit as a result.

The simplest use of this unit is to freeze-dry aseptically in vials. As many as 130 uncapped vials can be loaded into the box and sterilized by autoclaving. Samples are then loaded into vials, the lid attached, and the unit is placed in an ultralow freezer. After the samples freeze (e.g., after several hours) the unit is connected to a freeze-dryer via a quick release hose attached to one of the freeze-dryer ports (several configurations are possible). Small samples (e.g., 20 µl) are lyophilized in 1-2 hours while larger volumes require longer times. Following drying, a valve attached to the unit is closed, thus retaining a sterile vacuum environment, and the box is transferred to a sterile hood. The vacuum is released slowly and the tubes are removed and capped. As noted, the Freeze-Drying Unit is best used in conjunction with a laminar flow hood.

In a similar manner, microwell plates, preferably flat-bottomed plates, can be used to freeze-dry small samples. A special rack is enclosed for the microwell plate, and like the vials, samples are frozen in the wells and then dried.

Each unit includes the following items: Aluminum enclosure with double-plated lid with silicone gasket, solid brass vacuum control valve, and stainless steel latches and strikes. Aluminum rack for 72 2-mL vials. Aluminum microwell plate holding rack. Rack hook for removing racks aseptically. Vacuum tubing (2 feet). Hose clamps. Coupling set: one Female quick release valve, one male quick release fitting, one male/male 1/4 inch hose coupling, one 1/4 inch male 1/4 inch NPT fitting, one freeze-dryer port adaptor.

APPLICATION

The freeze-drying of small samples in vials and 96-well plates is increasing in popularity as the value of freeze-drying nucleic acids, peptides, and analytical samples increases. Not only does freeze drying increase the stability of biomolecules it greatly enhances the solubility of many molecular species, including RNA and peptides. Furthermore, the unit is designed to minimize exposure of the samples to contaminants.

Larger Picture

The two racks included with this freeze-drying unit are specifically designed to maximize freeze-drying in microwell plates and flat-bottomed 2 ml vials. Heat, which is needed to drive off water from the frozen sample, is readily transferred from the aluminum enclosure, to the rack, and then to the sample. For small volumes, freeze-drying occurs in a few hours.

OPERATION

The Microplate and Aseptic Vial Freeze-Drying unit is an add-on device to both bench-top and console freeze-dryer units. For aseptic freeze-drying, the device is autoclaved, and then loaded in a biosafety hood. The vacuum control valve is closed and opened after the unit is connected to the freeze-dryer. To maintain aseptic process, the vacuum control valve is closed, disconnected from the freeze-dryer, and opened after being placed in a biosafety hood.

Related Products

Microbial Freeze Drying Buffer

Lyophilization Reagent (2X)

Freeze Drying Indicator