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Labware caps are essential for maintaining sample integrity, preventing contamination, and ensuring safe storage and transportation of chemicals and biological materials. Selecting the appropriate cap for your specific application is crucial for accurate experimental results and laboratory safety. This guide will help you navigate the key considerations when choosing the right labware closures.
PEPTIDE CAPS FOR VIALS — COLOR-CODE AT A GLANCE Eight distinct colors make compatible vials easier to identify without checking every label. Turn a row of similar-looking vials into a clean, easy-to-read setup.
A BETTER-LOOKING PEPTIDE STORAGE SETUP Keep compatible vials easy to spot in a peptide case, vial box, fridge case or organizer. These bright vial lids and vial toppers bring color and order to everyday vial storage.
MADE FOR 13.5MM METAL CRIMP TOPS Designed for select 1ml, 2ml and 3ml glass vials with an existing metal or aluminum crimp cap measuring approximately 13.5mm / 0.53in across. For the best match, use the cap measurement rather than vial capacity.
FLEXIBLE SILICONE, MADE TO REUSE Soft silicone vial covers slip over compatible metal tops and are easy to remove and reuse. A simple, colorful upgrade for peptide accessories, storage supplies and vial organization.
Professional Leak-Proof Design: Made of high-quality materials and customized for 3ml glass ampoules and vials, it provides double leak-proof protection, effectively isolates moisture and contaminants, significantly extending the shelf life of reagents...
Efficient Color Classification and Management: 8 color schemes are available (purple, white, orange, blue, red, yellow, green, and black), each with its own unique characteristics. This allows for visual coding by date, ingredient, and priority...
Reusable and Easy to Clean：Using high-quality, chemically stable and corrosion-resistant materials, it withstands high-temperature cleaning and repeated use, resists aging and deformation, and ensures excellent sealing and hygienic performance over...
Convenient Operation and Easy Maintenance：Securely installs with a single click and allows for one-handed opening, making it suitable for frequent use. It can be washed and air-dried after use, simplifying maintenance and saving time and effort
MULTIPLE SIZES OF PEPTIDE VIAL CAPS Keep small and large peptide vial caps together in one practical set. The 15-piece assortment includes 10 small vial caps and 5 large vial covers, giving mixed vial collections more of the larger size commonly needed...
13.5MM SMALL CAPS + 20.4MM LARGE VIAL CAPS Some 1ml, 2ml and 3ml vials use a 13.5mm/0.53in metal seal, while some 5ml, 10ml and 30ml vials use a 20.4mm/0.8in metal seal. Measure across the widest outside edge of the existing aluminum seal—not the rubber...
COLOR-CODE YOUR VIAL STORAGE Ten assorted colors make similar-looking vials easier to identify at a glance. Organize different vial groups, separate storage categories and locate the vial you need faster inside a peptide case, vial box or fridge...
REUSABLE SILICONE VIAL LIDS AND TOPPERS Flexible silicone stretches over compatible metal vial tops for convenient placement and removal. Use them repeatedly as peptide lids, vial toppers, vial cap covers and protective outer covers during everyday...
Ample Quantity -- You will get a total of 30 pcs of 5 different sizes of resin bottle caps, 6pcs/size, the sufficient quantity is enough to meet your daily use needs.
Size Information - The 6 different sizes of bottle caps are about 21mm, 23mm, 24.5mm, 27.5mm, 31.5mm in height; 12mm, 12mm, 13mm, 13mm, 13.5mm in diameter; 16.5mm, 18mm, 20mm, 22mm, 26mm in inner diameter.
Premium Quality--These squeeze bottle lids are made of high quality plastic, which is durable, not easy to break, to ensure long-term use.
Wide Application--Multifunctional bottle caps are very suitable for condiments, cleaning products and many different products. It is very suitable for seasoning, glue, paint, and modeling and crafting activities. Ideal for squeeze bottles and plastic...
✅Protective 3ml Vial Caps Covers Peptide: Designed specifically for 1ml 2ml 3ml 4ml peptide vials, insulin vials or other 3ml glass vials. Reusable Silicone Peptide Vial Covers Fit Peptide Case for Fridge, Fits Vial Neck Diameters of 13-14.5mm...
✅Efficient Management with Black 3ml Vial Caps: This set includes 40PCS black vial caps and they offer excellent dust-proof protection, keeping vial contents clean in storage. With universal compatibility, these caps fit most standard 3ml glass vials...
✅Reduce Waste and Save Money: These glass vial caps specially designed for opened 3ml insulin vials / peptide vials / liquid vials, provide leak proof sealing protection. Effectively isolate moisture, significantly extending the shelf life of insulin...
✅Safe and Durable Material: These peptide lids made of soft silicone material, stretchable, Fits most 1ml 2ml 3ml 4ml vials. Compatible with the peptide vial case in the refrigerator. Easy to clean and reusable, just rinse with water, durable and...
Glow in the Dark Upgrade: These peptide vial caps absorb light and glow in low-light conditions, helping you find and identify glass vials in a fridge, vial case, storage box, travel bag, or cabinet.
Fits Popular Vial Sizes: Designed for common 3ml, 5ml, 10ml, and 30ml glass vials, and compatible with many 1ml-100ml glass vials. Also useful for vial caps 10ml, vial caps 30ml, and multi-size vial storage.
14 Pcs with 7-Color Coding: Includes 14 reusable silicone vial covers in 7 colors. Use them as color coded vial caps to sort vials by date, contents, priority, or daily use.
Reusable Silicone Protection: Flexible silicone vial caps help cover opened glass vials during storage and reduce exposure to dust, moisture, evaporation, and accidental spills. Easy to install, remove, clean, and reuse.
Complete 3ml & 5ml Peptide Vial Caps Pack: You get 20 x 3ml vial caps + 20 x 5ml vial caps, tailored for 3ml glass vial and 5ml glass vial. These peptide vial caps 5ml and peptide vial caps 3ml grip tightly, preventing loose vial caps covers and acting as...
Premium Food-Grade Silicone – Reusable Vial Caps: Made from food-grade silicone, our peptide caps 5ml and peptide caps 3ml are reusable and crack-proof. They serve as 3ml vial caps covers peptide solutions and 5ml vial caps covers peptide residues...
Green-colors Coding for Quick Peptide & Vial Identification: With a green color, these vial caps serve as peptide labels for 5ml vials, peptide labels for 3ml vials, and replace traditional 5ml vial labels and 3ml vial labels. Color-code by peptide type...
Dust-Proof, Moisture-Block Seal: Pop these caps onto pierced 5ml glass vials and 3ml glass vials to block airborne dust, moisture, and contaminants. As protective peptide vial caps, they safeguard rubber stoppers and reduce evaporation, keeping insulin...
Material: polyethylene;Inside Diameter: 45 mm / 1.77 inch. Suitable for GL45 Media Glass Bottles
Advantage: Our GL45 Screw Caps are made of polyethylene materials, which can autoclavable maximum temperature up to 140℃ / 284°F. Thermal performance, solvent resistance, autoclavable. Tight seal, leakproof, reduces the risk of liquid evaporation and...
These polyethylene caps are suitable for various industries and produce good sealing effects. They are suitable for sealing glass grow bottles, beer bottles, brewing containers, fermenting and brewing beer, wine, etc., making beer easy to carry on the...
Instruction: The polyethylene sealing screw cap has a raised ridge around the entire circumference, making it easier to hold and seal. Insert the phenolic resin cover into the sealing area to form a tight seal to prevent liquid leakage, providing you with...
Package & Size: You will get 6 pcs screw caps, the inner diameter is 22 mm/0.9 inch.Before purchasing, please confirm whether the outer diameter of the bottle mouth matches the inner diameter of the bottle cap, otherwise, it will not fit.
Material: These phenolic resin covers are made of pp plastic, are resistant to high temperatures and chemical corrosion, can be reused, and are suitable for storing various chemical reagents and samples to ensure storage safety.
Strong sealing: The bottle cap is designed to fit tightly with the bottle mouth to prevent liquid leakage or volatilization, which is conducive to sealing.
How to Install: To use the bottle caps, simply screw them onto bottles with compatible neck sizes. Twist the cap open when you need to dispense the contents and twist it closed securely after use to prevent any leakage or drying out.
Specification: Color: Purple; Material: Aluminum Plastic; Inner Size: 13 x 6.5mm / 0.51 x 0.26 Inch(Diameter*H); Outer Size: 15 x 8mm / 0.59 x 0.31 Inch(Diameter*H); Packing List: 250 Pcs x Vial Caps
Advantage: The aluminum layer can effectively block oxygen, water vapor and odor, preventing the contents from getting damp and oxidized. The cover is smooth after opening, and the cotton will not get caught. The seal can withstand high temperatures.
Application: Aluminum plastic caps are suitable for oral liquid bottles, original solution bottles, essential oil bottles, freeze-dried bottles, etc. Can be used in the lab and at home, with a great sealing effect and convenient storage.
Instruction: This cover is fully tear-off, and when you tear off its plastic cover, the aluminum cover becomes unusable.
Last update on 2026-10-15 / Affiliate links / Images from Amazon Product Advertising API
How to Choose the Best Labware Caps
Material Matters
The material of a labware cap significantly impacts its chemical resistance, temperature tolerance, and sealing capabilities.
Plastic Caps: Common plastics like polypropylene (PP) and polyethylene (PE) offer good chemical resistance for general use and are often autoclavable. PTFE-lined caps provide excellent chemical inertness, ideal for aggressive solvents.
Rubber and Silicone Caps: These offer good elasticity and sealing properties, often used for stoppers or septa. Silicone is preferred for higher temperatures and broader chemical resistance than natural rubber.
Metal Caps: Typically used for specific applications requiring high durability or extreme temperature resistance, often with liners for sealing.
Seal Type and Functionality
Consider how well the cap seals and its ease of use for your workflow.
Screw Caps: Provide a secure, airtight seal, preventing evaporation and contamination. Look for caps with liners for enhanced sealing, especially with volatile substances.
Snap Caps: Offer quick and easy sealing, suitable for applications where frequent access is needed, though they may not provide as robust a seal as screw caps.
Septa: Used for injection ports, allowing sterile sample withdrawal or introduction using a syringe.
Compatibility with Labware
Ensure the cap is designed to fit the specific neck finish or opening of your labware, whether it's a bottle, vial, tube, or flask. Mismatched caps can lead to leaks or failure to seal properly, compromising your samples. Always check neck finish standards (e.g., GL45, 13-425) to guarantee a proper fit.
Frequently Asked Questions
What is the difference between a screw cap and a snap cap?
Screw caps offer a more secure and airtight seal by threading onto the container, ideal for long-term storage and preventing evaporation. Snap caps, on the other hand, press or snap into place for quick and easy sealing, suitable for frequent access.
Are plastic caps safe for use with chemicals?
Most common plastic caps made from materials like polypropylene or polyethylene offer good resistance to a wide range of chemicals for general laboratory use. For highly corrosive or reactive substances, caps with PTFE liners are recommended for superior chemical inertness.
Can I autoclave labware caps?
Many plastic caps, particularly those made from polypropylene (PP), are designed to be autoclavable. It is essential to check the product specifications for the specific cap material and its temperature tolerance to ensure it can withstand the autoclaving process without deforming or degrading.
What does 'neck finish' mean for labware caps?
Neck finish refers to the standardized size and thread specification of the opening on a labware item like a bottle or vial. Ensuring the cap's neck finish matches the labware's is critical for achieving a secure and leak-proof seal.
When should I use a cap with a liner?
Caps with liners are recommended when a superior seal is required, especially for volatile liquids, aggressive chemicals, or when preventing contamination is paramount. Liners provide an extra layer of protection against leaks and evaporation, ensuring sample integrity.
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