Sterile Two-Position Snap Caps for 12 mm PP Test Tubes — LDPE, Natural, 1000/Bag (222-3812-02P)
These sterile Low-Density Polyethylene snap caps are designed to fit 12 mm outer-diameter polypropylene test tubes, providing a reliable two-position closure mechanism in a 1000/Bag bulk supply format. Position 1 holds the cap partially open for gas exchange during incubation, culture, or centrifugation, while Position 2 delivers a fully sealed closure for storage, transport, and aerosol containment. The inherent flexibility of LDPE allows the snap mechanism to engage consistently with the dimensional tolerances of standard PP tube walls.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 222-3812-02P |
| Product Type | Two-Position Snap Caps |
| Cap Material | Low-Density Polyethylene (LDPE) |
| Color | Natural |
| Compatible Tube Diameter | 12 mm OD |
| Compatible Tube Material | Polypropylene (PP) |
| Cap Positions | Position 1: Vented (partial open); Position 2: Fully closed |
| Sterility | Sterile |
| Pack Size | 1000/Bag |
| BPA / Phthalate / Latex | BPA-Free, Phthalate-Free, Latex-Free |
| Country of Origin | USA |
Applications
- Cell culture: vented position (Position 1) permits CO₂ exchange during incubation; sealed position (Position 2) secures tubes for transport between the incubator and biosafety cabinet
- Centrifugation: vented position equalizes pressure during spins on 12 mm PP round-bottom tubes, reducing cap ejection and sample loss
- Flow cytometry sample preparation: vented closure during antibody incubation steps, then snapped fully closed before acquisition
- Serology and agglutination panels: re-seal 12 mm PP tubes after reading for continued incubation without aerosol risk
- Bulk cap inventory and replacement supply: high-volume labs processing large daily tube counts benefit from the 1000/Bag format and sterile assurance
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers / saline | Excellent |
| Cell culture media | Excellent |
| Dilute acids and bases | Good |
| Ethanol (<70%) | Good — short-term contact |
| Methanol (<50%) | Good — short-term contact |
| Acetonitrile | Not recommended |
| Chlorinated solvents (e.g., chloroform) | Not recommended |
Quality & Procurement
Made in USA, these Caplugs® Evergreen snap caps are manufactured from BPA-free, phthalate-free, and latex-free LDPE resin, supplied sterile and ready for immediate use in regulated and research environments. LabSupplies.com is an authorized Caplugs® Evergreen dealer, shipping from USA inventory with same-business-day dispatch available on stocking items. Volume and institutional pricing is available for high-throughput labs and procurement teams managing recurring consumable spend.
Frequently Asked Questions
Are these caps supplied sterile, and do they require any pre-treatment before use?
Yes — the 222-3812-02P caps are sterile as supplied and require no additional sterilization before use in cell culture, clinical, or other contamination-sensitive workflows.
What is the difference between Position 1 and Position 2 on these snap caps?
Position 1 holds the cap in a partially open, vented state that allows gas exchange — useful during centrifugation, CO₂ incubation, or any step requiring pressure equalization. Position 2 snaps the cap fully closed to create a sealed barrier for storage, transport, or aerosol containment.
Will these caps fit polystyrene (PS) test tubes of the same diameter?
These caps are optimized for 12 mm OD polypropylene tubes. For 12 mm PS tubes, Caplugs® Evergreen offers part number 222-3812-02S, which is dimensioned for the PS tube wall tolerances.
Can I autoclave these LDPE caps to re-sterilize them?
LDPE is generally not recommended for autoclaving, as elevated temperatures can cause deformation that may compromise the snap-fit mechanism. These caps are intended as single-use sterile consumables; the 1000/Bag pack size supports that workflow economically.