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
West Pharmaceutical Services Inc WEST PHARMACEUTICAL SERVICES INC
NC3946553 20MM-DAIKYO-D-SIGMA-CHLOROBUTY
Chemglass Life Sciences Rubber Stopper, #9, One Hole, Black
Rubber Stopper, #9, One Hole, Black. These stoppers are suitable for practically all general laboratory uses. Composition ensures resiliency and pliability over a long period and withstands laboratory conditions without hardening. The dimensions are in accordance with specifications established by the N.B.S. and are low in free sulfur (1/2%). Autoclavable at 250F for 30 minutes under water or steam conditions only (not dry heat). End user must test for their specific application. Diameter: Top (45mm), Bottom (37mm). Length: (25mm). Diameter of hole: (5mm).
Electron Microscopy Sciences Vacule Lyophylization Stoppers, 2 Prong
Heavy wall construction, designed for lyophilization and freeze-drying. Manufactured from Wheaton 33 low extractable borosilicate glass (meets ASTM Type I Class and USP Type I Standards). Accessory for 4 ml Vacule Vials.
Mitegen Au-Flat TEM Grid, 2µm Hole Pattern on 200 Gold Mesh, For Cryo-EM Sample Preparation,
The Au-Flat TEM Grid features a precise 2 µm hole pattern on a robust 200 gold mesh, making it an essential component for high-resolution cryo-electron microscopy (cryo-EM) sample preparation. Crafted from high-quality gold, this grid offers excellent conductivity and stability, which are critical for optimal imaging performance and minimizing sample drift in cryogenic environments. The uniform hole pattern facilitates consistent ice thickness and particle distribution, crucial for achieving high-quality data. Designed for reliability and ease of handling, these grids support a streamlined workflow for vitrification and subsequent imaging. They provide a stable and optically clear substrate for delicate biological specimens, contributing to enhanced resolution and reproducibility in structural biology research. This product is supplied in a convenient box of 50 grids, ensuring an ample supply for demanding, high-volume experimental needs in cryo-EM.
West Pharmaceutical Services Inc 20mm NovaPure® Ready-to-Sterilize Bromobutyl 4023/50 Serum Stoppers, Qty. 3,000 stoppers/bag
NovaPure® serum stoppers are made from 4023/50 a premium quality bromobutyl elastomer with West’s lowest particulate specification available. Laminated with FluroTec™ barrier film to help reduce particulate, limit drug interaction with the elastomer and reduce leachables. These components are provided washed (ready-to-sterilize) and 100% vision inspected. This stopper configuration can be used with European blowback, North American blowback, or straight wall (no blowback) vials. West item number: 70025047
Grainger Stopper Sz 7 30 mm BDia Black 0 PK15
The Grainger 16ZD64 is a 3M Scotch-Brite General Purpose Hand Pad that can be used for cleaning and scouring. It features an open web construction with non-woven fibers that are non-scratching on most surfaces. This 6 inch by 9 inch hand pad has a medium duty abrasiveness level. It can be used wet or dry for scrubbing, wiping and polishing. The 3M Scotch-Brite material resists fraying and tearing.