20 mL Vial & 30 mL Centrifuge Tube Screw Caps — HDPE, Natural, 1000/Bag (300-3532-020)
These natural High-Density Polyethylene (HDPE) screw caps from Caplugs® Evergreen are designed for 20 mL screw-neck vials and 30 mL centrifuge tubes, offering a larger thread specification than the 15 mL cap family (300-3010 / 300-3022) to match the wider neck geometry of large-format tubes. Supplied non-sterile in 1000/Bag quantities, part number 300-3532-020 delivers IATA P650 compliant leak-free closure, cryogenic stability to -80°C, and autoclave compatibility at 121°C — making it a versatile all-purpose cap for biobanking, specimen transport, and cell culture programs alike.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 300-3532-020 |
| Cap Type | Screw cap — threaded engagement |
| Material | High-Density Polyethylene (HDPE) |
| Color | Natural |
| Tube Compatibility | 20 mL screw-neck vials; 30 mL centrifuge tubes |
| Thread Note | Larger thread specification than 300-3010 / 300-3022 (15 mL cap family) |
| IATA P650 | Compliant — leak-free primary container seal |
| Cryogenic Storage | Compatible — -20°C and -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 large-volume serum, plasma, and urine specimen archiving
- Sealing 30 mL centrifuge tubes for IATA P650 compliant biological specimen transport via courier
- Cryogenic biorepository storage at -20°C and -80°C with HDPE thread integrity through repeated freeze-thaw cycling
- Pre-sterilized cap supply for cell culture and pathogen-handling workflows following autoclave processing at 121°C
- Capped centrifugation for serum separation in 30 mL tube formats — screw-thread retains engagement under centrifugal force
- Universal tube programs and color-coded batch routing workflows where natural caps serve as the default unassigned color
Compatibility
The 300-3532-020 cap is sized for Caplugs® Evergreen 20 mL screw-neck vials and 30 mL centrifuge tubes. Its thread specification is intentionally larger than the 300-3010 plain cap and 300-3022 sprocket cap used with 15 mL tubes — the two families are not interchangeable. Laboratories running both 15 mL and 30 mL centrifuge tube programs should stock both cap families separately and confirm thread fit with their specific tube lot before placing a bulk order. Where color-differentiated closure is needed for the same tube format, the 300-3532 series is also available in Blue (300-3532-B20) and Dark Green (300-3532-DG20).
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers, saline, PBS | Excellent |
| Serum, plasma, urine, biological specimens | Excellent |
| Dilute acids and bases | Good |
| Short-chain alcohols (ethanol, isopropanol) | Good — short-term contact |
| DMSO (working concentrations) | Good — short-term contact |
| Acetone / aromatic solvents | Not recommended |
| Chlorinated solvents (chloroform, DCM) | Not recommended |
| Autoclave (121°C / 15 psi) | Compatible |
| Cryogenic storage (-80°C) | Compatible |
Quality & Procurement
Made in USA at Caplugs® Evergreen's California manufacturing facility, these caps are produced from BPA-free, phthalate-free HDPE resin under ISO 9001 quality management. The IATA P650 compliant leak-free seal meets international biological specimen transport requirements without secondary containment modification. LabSupplies.com is an authorized Caplugs® Evergreen dealer shipping from USA inventory, with institutional and volume pricing available for hospitals, biobanks, and research laboratories procuring at scale.
Frequently Asked Questions
Will these caps fit my existing 15 mL centrifuge tubes?
No — the 300-3532 series uses a larger thread specification designed for 20 mL vials and 30 mL centrifuge tubes. For 15 mL tube capping, use the 300-3010 (plain) or 300-3022 (sprocket) cap families instead. Always validate thread fit with your specific tube lot before bulk purchase.
Are these caps safe for biological specimen transport by air courier?
Yes — the threaded engagement provides an IATA P650 compliant leak-free primary container seal, making these caps appropriate for transport of serum, plasma, urine, and other biological specimens in 20 mL vials and 30 mL centrifuge tube formats.
Can these caps be autoclaved for sterile cell culture use?
Yes — HDPE construction is autoclave compatible at 121°C / 15 psi. Laboratories requiring a pre-sterilized cap supply for cell culture or pathogen-handling programs can autoclave these caps prior to use.
Are these caps suitable for ultra-low temperature biorepository storage?
Yes — HDPE maintains thread integrity and cap engagement at both -20°C and -80°C, making these caps appropriate for long-term frozen archive programs with repeated freeze-thaw cycling. Verify compatibility with your specific tube lot and storage protocol before committing to a large inventory purchase.