Sterile Two-Position Snap Caps for 12 mm PS Test Tubes — LDPE, Natural, 1000/Bag (222-3812-02S)
These sterile Low-Density Polyethylene snap caps are designed to fit 12 mm outer-diameter polystyrene test tubes, providing a reliable two-position closure mechanism in a convenient 1000/Bag format. Position 1 delivers a vented (partial-open) configuration for gas exchange during incubation, centrifugation, or cell culture, while Position 2 provides a fully sealed closure for storage, transport, and aerosol containment. The inherent flexibility of LDPE enables the snap mechanism to engage consistently with PS tube wall tolerances.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 222-3812-02S |
| Product Type | Two-Position Snap Caps for 12 mm PS Test Tubes |
| Cap Material | Low-Density Polyethylene (LDPE) |
| Color | Natural |
| Compatible Tube Diameter | 12 mm OD |
| Compatible Tube Material | Polystyrene (PS) |
| 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 in 12 mm PS tubes — vented position supports CO₂ exchange during incubation; closed position secures tubes for transport
- Centrifugation with pressure equalization — vented position prevents pressure buildup during spins in clinical or research centrifuges
- Serology agglutination panels — re-seal 12 mm PS tubes after initial reading to continue incubation steps
- Flow cytometry sample preparation — vented position during antibody staining incubations; closed position for acquisition on the instrument
- Bulk cap inventory for high-volume tube processing labs consuming caps at high daily rates
- Replacement cap supply for damaged or missing closures on 12 mm PS tube racks
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers / saline | Excellent |
| Cell culture media | Excellent |
| Ethanol (<70%) | Good — short-term contact |
| Methanol (<50%) | Good — short-term contact |
| Acetonitrile | Not recommended |
| Chlorinated / aromatic solvents | Not recommended |
Quality & Procurement
Made in USA, these Caplugs® Evergreen snap caps are manufactured from BPA-free, phthalate-free, and latex-free LDPE resin, making them appropriate for direct biological contact applications. LabSupplies.com is an authorized Caplugs® Evergreen dealer and ships from USA inventory, typically same business day for stocking items. The 1000/Bag pack size is well suited to high-throughput labs seeking to minimize per-cap cost and replenishment frequency; volume and institutional pricing is available upon request.
Frequently Asked Questions
Are these snap caps supplied sterile?
Yes — the 222-3812-02S is supplied sterile, making it ready for direct use in cell culture, clinical tube preparation, and other applications where sterility is required.
What is the difference between the two cap positions?
Position 1 is a vented, partial-open configuration that permits gas exchange — useful during incubation or centrifugation. Position 2 is fully closed for an aerosol-containment seal during storage or transport.
Will these caps fit polypropylene (PP) test tubes?
These caps are optimized for 12 mm OD polystyrene (PS) tube dimensions. For PP tubes, Caplugs® Evergreen offers the 222-3812-02P, which is designed for the dimensional tolerances of 12 mm PP tubes.
Can LDPE caps be autoclaved for re-sterilization?
LDPE is generally not recommended for autoclaving. Because these caps are supplied sterile, they are intended for single-use in sterile workflows rather than re-sterilization cycles.