20 mL Vial & 30 mL Centrifuge Tube Screw Caps — HDPE, Green, 1000/Bag (300-3532-G20)
These green High-Density Polyethylene screw caps from Caplugs® Evergreen are designed to fit 20 mL screw-neck vials and 30 mL centrifuge tubes, providing a leak-free threaded closure for clinical, biorepository, and field-collection workflows. Supplied non-sterile in convenient 1000/Bag quantities, the 300-3532-G20 supports IATA P650 compliant biological specimen transport, ultra-low temperature storage to -80°C, and autoclave sterilization at 121°C — making these caps versatile across the full specimen life cycle.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 300-3532-G20 |
| Cap Type | Screw cap — threaded engagement |
| Material | High-Density Polyethylene (HDPE) |
| Color | Green |
| Tube Compatibility | Caplugs® Evergreen 20 mL screw-neck vials; 30 mL centrifuge tubes |
| Thread Note | Larger thread than 300-3010/300-3022 (15 mL cap family) — not interchangeable |
| IATA P650 | Compliant — leak-free primary container seal |
| Cryogenic Storage | Compatible to -80°C |
| Autoclave Compatibility | Compatible (121°C / 15 psi) |
| Sterility | Non-Sterile |
| BPA / Phthalates | BPA-free; no phthalate plasticizers |
| Pack Size | 1000/Bag |
| Country of Origin | USA (California) |
Applications
- Capping 20 mL screw-neck vials for serum, plasma, urine, or other clinical specimens prior to transport or archiving
- Securing 30 mL centrifuge tubes during centrifugation for serum separation or cell pelleting — threaded engagement retains the cap through centrifuge forces
- IATA P650 compliant biological specimen transport in leak-proof primary containers
- Ultra-low temperature biorepository archiving of large-format tubes at -80°C cryo storage conditions
- Color-coded batch and specimen-type routing in multi-analyte or multi-site clinical laboratories — green designates a specific category within a 15-color system
- Cell culture in 30 mL tubes where HDPE is compatible with standard culture media formulations
- Environmental sampling with large-volume field collection tubes requiring chemically inert closures
- Replacement cap program for existing 20 mL vial or 30 mL centrifuge tube inventory with matching Caplugs® thread geometry
Compatibility
These caps are engineered to fit Caplugs® Evergreen 20 mL screw-neck vials and the 30 mL centrifuge tube family. The 300-3532 series uses a larger thread specification than the 300-3010 and 300-3022 cap families designed for 15 mL tubes — the two families are not interchangeable. If you are sourcing replacement caps for an existing inventory of Caplugs® 20 mL vials or 30 mL centrifuge tubes, these caps will match the thread geometry precisely. Always validate fit with a sample quantity before committing to a bulk purchase if you are unsure of your tube format.
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers, saline, water | Excellent |
| Dilute acids and bases | Excellent |
| Alcohols (ethanol, methanol) | Good — short-term contact |
| Environmental matrices (water, soil eluates) | Excellent |
| Chlorinated solvents (chloroform, DCM) | Not recommended |
| Aromatic solvents (toluene, xylene) | Not recommended |
| Autoclave (121°C / 15 psi steam) | Compatible |
| Cryogenic storage (-80°C) | Compatible |
Quality & Procurement
Made in USA at Caplugs® Evergreen's California facility, these screw caps are manufactured from BPA-free, phthalate-free HDPE resin under ISO quality management standards. All 15 colors in the 300-3532 series share identical material specification and thread geometry — only the color varies — so procurement teams can standardize on a single part family for multi-color routing systems without qualifying separate materials. LabSupplies.com is an authorized Caplugs® Evergreen dealer shipping from USA inventory, with tiered pricing available for high-volume institutional, clinical, and biorepository accounts.
Frequently Asked Questions
Will these caps fit my existing 15 mL centrifuge tubes?
No. The 300-3532 series uses a larger thread specification than the 300-3010 and 300-3022 cap families, which are designed for 15 mL tubes. These green caps are compatible only with Caplugs® Evergreen 20 mL screw-neck vials and 30 mL centrifuge tubes. If you are unsure of your tube format, request a sample quantity to verify fit before placing a bulk order.
Are these caps suitable for transporting infectious or diagnostic specimens?
Yes — these caps provide an IATA P650 compliant leak-free closure when properly threaded onto compatible Caplugs® Evergreen vials or centrifuge tubes, making them appropriate for regulated biological specimen transport.
Can these caps be autoclaved for sterile supply preparation?
Yes. The HDPE material is compatible with standard autoclave cycles at 121°C / 15 psi. Note that the caps are supplied non-sterile from the factory, so autoclave sterilization must be performed by your facility if sterile closures are required for your application.
Why are 15 different cap colors available in the 300-3532 range?
Color coding is widely used in clinical and research laboratories to differentiate specimen types, processing batches, collection sites, or priority levels at a glance — reducing routing errors without additional labeling. All 15 colors in the 300-3532 series share the same HDPE material and thread geometry, so a single procurement decision covers an entire color-coded workflow.