Stoppers
Stoppers, also known as bungs, are used to give an airtight seal to laboratory flasks and test tubes by fitting tightly inside the neck of the container and preventing material from spilling. Stoppers can be made of glass, cork, rubber, or silicone. They are typically designed with a conical shape, but straight, flanged, and tapered options are also available.
Stoppers are the preferred choice for many applications requiring a tighter seal or a greater degree of chemical resistance. They also provide a good seal when a solution needs to be shaken or mixed without spilling. Stoppers are generally cylindrical in shape and have a tapered bottom end. They may be marked with a stopper number or size on the top and bottom diameters of the stopper. Sizing can vary among manufacturers.
Stoppers are available in a solid design or with holes known as positions placed in the top. Positions allow easy access to the material contained in the sealed vessel by pipettes, tubing, or other equipment without full removal of the stopper.
What Types of Stoppers Are Available?
• Turnover stoppers have external serrations to create an excellent internal seal combined with a flexible turnover sleeve that folds down over the container’s neck to create a double seal
• Serum bottle or vial stoppers have two or three legs with external serrations or straight sides and a flanged top to create an airtight seal
• Straight bromobutyl plug-type stoppers provide a maximum seal for vials and serum bottles with a straight-wall glass finish
• Ultra-pure, straight bromobutyl plug-type stoppers provide high chemical purity and low gas permeability. They offer excellent performance during freeze drying processes such as lyophilization, where stoppers must remain stable during transfer and sublimination phases
• Silicone recessed septa stoppers are non-toxic and have external serrations to create an effective internal seal
DWK Life Sciences KIMBLE™ KONTES™ Silicone Filtration Stoppers
KIMBLE™ KONTES™ Silicone Filtration Stoppers are designed for use with filtration assemblies, providing a secure, flexible seal. Made from high-quality silicone, these stoppers offer chemical resistance and reliable performance in laboratory filtration applications.
DWK Life Sciences WHEATON™ Ultra Pure OmniFlex Pure Stoppers
WHEATON™ Ultra Pure OmniFlex Pure Stoppers. Featuring PTFE-like coatings to prevent reactions due to sample contact with rubber, WHEATON™ Ultra Pure OmniFlex Pure Stoppers are manufactured in a silicone-free environment and are completely coated with a fluorinated polymer.
Fisherbrand™ One-Hole Rubber Stoppers
One hole rubber stopper
DWK Life Sciences KIMBLE™ KONTES™ Hollow White Rubber Sleeve Stoppers
KIMBLE™ KONTES™ Hollow White Rubber Sleeve Stoppers fit securely into the neck of glassware apparatus. The plug-type design with sleeve extension provides a reliable seal, and the diaphragm can be punctured with a syringe needle. Rated for use up to 125°C for up to 8 hours.
Corning™ PYREX™ Hollow Glass Standard Taper Stoppers
Variety of sizes available
Corning™ PYREX™ Solid Glass Pennyhead Standard Taper Stoppers
For use with flask and separatory funnel
DWK Life Sciences KIMBLE™ KIMAX™ Brand Pennyhead Stoppers
KIMBLE™ KIMAX™ Brand Pennyhead Stoppers are medium length standard taper glass stoppers for use with laboratory glassware such as flasks, mixing cylinders, and separatory funnels. Manufactured from borosilicate glass conforming to USP Type I and ASTM E438, Type I, Class A requirements.
DWK Life Sciences WHEATON™ Sleeve Style Stoppers for Vials without Crimp Closure
WHEATON™ Sleeve Style Stoppers for Vials without Crimp Closure feature a fold-over skirt for sealing in serum finish vials without a crimp closure, providing a reliable injection site for multiple dose entry.
DWK Life Sciences WHEATON™ Flange Style Rubber Stopper
WHEATON™ Flange Style Rubber Stopper is designed for research and parenteral drug applications. Siliconized halobutyl construction in a two-leg lyophilization style ensures reliable sealing performance for vials.
Synthware™ Flask Length Penny-Head Stopper
Various Joint Sizes Available.
DWK Life Sciences WHEATON™ Stoppers for Serum Bottles and Vials: Snap-on Stopper
WHEATON™ Stoppers for Serum Bottles and Vials: Snap-on Stopper provide airtight sealing for serum bottles and vials. Flange-type stoppers are secured with aluminum crimp seals; slotted and three-prong plug stoppers suit freeze-dry applications.
DWK Life Sciences KIMBLE™ Two-Leg Lyophilization Serum Bottle and Vial Stoppers
KIMBLE™ Two-Leg Lyophilization Serum Bottle and Vial Stoppers are designed for research and pharmaceutical packaging applications. Free from plasticizers, nitrosamine precursors, and natural rubber latex, with a universal gray chlorobutyl formulation meeting USP, EP, and JP requirements.
DWK Life Sciences DURAN™ Grey Bromobutyl Rubber Stopper, Straight Plug, for GL 25 or GL 45 Laboratory Bottles
DURAN™ Grey Bromobutyl Rubber Stopper, Straight Plug, for GL 25 or GL 45 Laboratory Bottles provides a gas-tight seal for GL 25 and GL 45 bottles. Bromobutyl rubber is impermeable to most gases, supports anaerobic conditions, and allows multiple syringe punctures.
Fisherbrand™ Silicone Recessed Septum Stoppers
Nontoxic and autoclavable recessed septum stoppers are externally serrated to create an effective internal seal