20 mL Vial & 30 mL Centrifuge Tube Screw Caps — HDPE, Blue, 1000/Bag (300-3532-B20)
These blue High-Density Polyethylene screw caps are designed to seal Caplugs® Evergreen 20 mL screw-neck vials and 30 mL centrifuge tubes, providing a leak-free threaded closure rated to IATA P650 for biological specimen transport. This cap carries a larger thread specification than the 15 mL cap family (300-3010 and 300-3022), sized precisely for the wider neck of 20 mL and 30 mL format tubes, and ships non-sterile in economical 1000/Bag quantities ready for high-throughput clinical and research workflows.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 300-3532-B20 |
| Cap Type | Screw cap — threaded engagement |
| Material | High-Density Polyethylene (HDPE) |
| Color | Blue |
| Compatible Tubes | Caplugs® Evergreen 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 at −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
- Large-volume specimen transport: IATA P650-compliant threaded closure securely seals serum, plasma, and urine in 20 mL vials and 30 mL centrifuge tubes for clinical courier transport and inter-laboratory transfers
- Color-coded batch routing: Blue caps enable visual specimen-type differentiation consistent with CLSI H3 color-coding conventions — designating citrate anticoagulant or coagulation specimen batches without secondary labels
- Frozen biorepository archiving: HDPE construction maintains thread integrity and cap seal through repeated freeze-thaw cycling at −20°C and −80°C, making these caps suitable for large-format cryostorage programs
- Capped centrifugation: The screw-thread engagement retains closure during centrifugation for serum and plasma separation workflows in 30 mL centrifuge tubes
- Pre-sterilized cell culture and pathogen programs: Autoclave compatibility at 121°C allows labs to sterilize capped tubes or a bulk cap supply before use in sterile processing workflows
Compatibility
These caps are designed to fit Caplugs® Evergreen 20 mL screw-neck vials and 30 mL centrifuge tubes. The thread geometry of this cap is specifically sized for those larger tube formats and is not interchangeable with the 15 mL cap family — caps in the 300-3010 (plain) and 300-3022 (sprocket) lines use a smaller thread specification. Laboratories transitioning from 15 mL tube programs should validate thread fit with their specific 20 mL or 30 mL tube format before placing a bulk order. Alternative color options include 300-3532-020 (Natural) and 300-3532-DG20 (Dark Green) for programs using multi-color routing schemes.
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers, saline, biological matrices | Excellent |
| Dilute acids and bases | Good |
| Short-chain alcohols (ethanol, IPA) | Good — suitable for working concentrations |
| DMSO (working concentrations) | Good |
| Chlorinated solvents (chloroform, DCM) | Not recommended |
| Aromatic solvents (toluene, xylene) | Not recommended |
Quality & Procurement
Made in USA (California), these Caplugs® Evergreen screw caps are produced from BPA-free, phthalate-free HDPE resin under ISO quality manufacturing controls. IATA P650 compliance and autoclave rating at 121°C reflect the consistent material and dimensional standards the Evergreen line is built on. LabSupplies.com is an authorized Caplugs® Evergreen dealer, shipping from USA inventory with tiered pricing available for hospitals, clinical laboratories, biorepository programs, and research institutions purchasing at volume.
Frequently Asked Questions
Will these caps fit my existing 15 mL centrifuge tubes?
No — this cap uses a larger thread specification designed for 20 mL screw-neck vials and 30 mL centrifuge tubes. For 15 mL tube caps, see the 300-3010 or 300-3022 families. Always validate thread fit with your specific tube format before bulk purchase.
Are these caps safe for ultra-low temperature storage at −80°C?
Yes. HDPE maintains dimensional stability and thread integrity through freeze-thaw cycling at both −20°C and −80°C, making these caps suitable for biorepository programs archiving large-format tubes at ultra-low temperatures.
Can I autoclave these caps before use?
Yes — the caps are compatible with standard autoclave cycles at 121°C / 15 psi, allowing pre-sterilization for cell culture, pathogen containment, or other sterile processing workflows.
What does IATA P650 compliance mean for my shipping program?
IATA Packing Instruction P650 governs the transport of exempt human or animal specimens. A P650-compliant closure — like the threaded engagement on these caps — provides a leak-free primary container seal, which is one of the required containment layers for compliant biological specimen shipment by air courier.