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
Fisherbrand™ Solid Rubber Stoppers
Offers higher resilience, flexibility and can withstand many chemical agents in normal laboratory use.
Lenz Laborglasinstrumente™ Pointed Bottom Hollow Stoppers, Hexagonal Plate
For the safe and secure closure of flasks, bottles, tubing and other laboratory apparatus. Lenz Laborglasinstrumente™ Pointed Bottom Hollow Stoppers, Hexagonal Plate are manufactured from durable DURAN™ borosilicate glass.
DWK Life Sciences KIMBLE™ Straight-Sided Serum Stoppers
KIMBLE™ Straight-Sided Serum Stoppers are designed for research and pharmaceutical packaging applications. The universal gray chlorobutyl formulation meets USP, EP, and JP requirements and is free of plasticizers, nitrosamine precursors, and natural rubber latex.
Cole-Parmer™ Twistit Stoppers, Rubber
Use these versatile Rubber Twistit Stoppers as solid, one-hole, two-hole, or three-hole stoppers.
Fisherbrand™ White Polyurethane Foam Stoppers
Used as convenient alternative method for closing sterile media flasks and vials instead of cotton plugs.
Fisherbrand™ Polyurethane Foam Stoppers
Formed by polymerization in the presence of a foaming agent.
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.
Kartell™ Rubber One-Hole Stoppers
Manufactured from rubber to ensure a tight fit. Kartell™ Rubber One-Hole Stoppers seal and secure medium in a bottle while providing tubing access.
Heinz Herenz Steristoppers No. MA2/3 for Glasses
Steristoppers™ have been proven as an excellent sealing for microbiological samples and tissue cultures in test tubes and Erlenmeyer flasks. They are in constant use in many European micro biological laboratories for many years.
Kartell™ Silicon Conical Stoppers
Constructed of silicon to make these stoppers suitable for applications involving food. Kartell™ Silicon Conical Stoppers are availavle in a variety of sizes to plug a variety of holes.
Heinz Herenz Steristoppers No.29K for Glasses
Steristoppers™ have been proven as an excellent sealing for microbiological samples and tissue cultures in test tubes and Erlenmeyer flasks. They are in constant use in many European microbiological laboratories for many years.