20 mL Vial & 30 mL Centrifuge Tube Screw Caps — HDPE, Assorted Colors, 1000/Bag (300-3532-X20)
These Caplugs® Evergreen HDPE screw caps fit 20 mL screw-neck vials and 30 mL centrifuge tubes, supplied as an assorted color mix of 1000 caps per bag. Part number 300-3532-X20 is the ideal entry point for laboratories evaluating a color-coded specimen routing system — every cap in the bag shares the same thread geometry, material specification, and performance ratings as the individual single-color 300-3532 variants, making it easy to trial color assignments before committing to single-color bulk orders. All caps are non-sterile, BPA-free, and rated for both –80 °C cryogenic storage and autoclave sterilization at 121 °C.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 300-3532-X20 |
| Cap Type | Screw cap — threaded engagement |
| Material | High-Density Polyethylene (HDPE) |
| Color | Assorted (mixed colors from 300-3532 range) |
| Compatible Tubes | Caplugs® Evergreen 20 mL screw-neck vials; 30 mL centrifuge tubes |
| Thread Note | Larger thread than 300-3010/300-3022 — not interchangeable |
| Cryogenic Storage | Compatible to –80 °C |
| Autoclave Compatibility | 121 °C / 15 psi |
| Leak Compliance | IATA P650 compliant leak-free closure |
| Sterility | Non-Sterile |
| BPA / Phthalates | BPA-free; phthalate-free |
| Pack Size | 1000/Bag |
| Country of Origin | USA (California) |
Applications
- Color-coded specimen routing — assign a distinct cap color to each specimen type, patient population, or workflow stream across clinical and research labs
- Capping and sealing 20 mL screw-neck vials for biorepository archiving and long-term frozen storage at –80 °C
- Sealing 30 mL centrifuge tubes through centrifugation — threaded engagement retains the cap securely under centrifuge forces
- Pediatric specimen programs — pink cap convention provides an immediate visual designation for pediatric batch routing
- Replacement cap supply for existing 20 mL vial and 30 mL centrifuge tube inventories
- Trialing a multi-color routing protocol before transitioning to single-color bulk orders that optimize per-cap cost
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers / saline | Excellent |
| Dilute acids and bases | Excellent |
| Alcohols (ethanol, isopropanol) | Good |
| Many organic solvents | Good — verify with specific solvent before use |
| Chlorinated / aromatic solvents | Not recommended |
| Cryogenic storage (–80 °C) | Compatible |
| Autoclave (121 °C / 15 psi) | Compatible |
Quality & Procurement
Made in USA at Caplugs® Evergreen's California facility, these HDPE screw caps are manufactured from BPA-free, phthalate-free resin under ISO quality management. LabSupplies.com is an authorized Caplugs® Evergreen dealer and ships from USA inventory, typically same business day for stocking items. The assorted-color 300-3532-X20 bag is the lowest-commitment format in the 300-3532 range — once your color routing protocol is established, transitioning to single-color bulk orders is straightforward. Tiered pricing is available for institutional and grant-funded laboratories.
Frequently Asked Questions
What tube sizes do these caps fit?
These caps are designed for Caplugs® Evergreen 20 mL screw-neck vials and 30 mL centrifuge tubes. They use a larger thread than the 300-3010 and 300-3022 cap families and are not interchangeable with those sizes, so confirm your tube's thread specification before ordering.
Can these caps be autoclaved or used for frozen storage?
Yes — the HDPE material is compatible with autoclave sterilization at 121 °C / 15 psi and with cryogenic storage down to –80 °C. All caps in the assorted bag share the same material and performance ratings as the single-color 300-3532 variants.
What colors are included in the assorted bag, and will they always be the same?
The bag contains a mix of colors drawn from the 300-3532 range. The specific color distribution may vary between bags — the assorted format is intended for trialing color routing assignments rather than for protocols that require a fixed set of colors. Once you have identified the colors that fit your workflow, single-color bulk orders are available.
Are these caps sterile?
No — they are supplied non-sterile. Laboratories requiring sterile closures should autoclave the caps using the 121 °C / 15 psi cycle prior to use.