Sterile Two-Position Snap Caps for 17 mm PP Test Tubes — LDPE, Natural, 1000/Bag (222-3817-02P)
These sterile Low-Density Polyethylene (LDPE) snap caps are designed for 17 mm outer-diameter polypropylene test tubes, offering two functional positions — vented (partially open) for gas exchange and fully closed for sealed storage or transport. Supplied in bulk at 1000 caps per bag, part number 222-3817-02P is ideal for high-throughput laboratories that need a reliable, cost-effective sterile closure for round-bottom PP tubes. The natural (translucent) color allows quick visual inspection of tube contents without removing the cap.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 222-3817-02P |
| Cap Material | Low-Density Polyethylene (LDPE) |
| Color | Natural (translucent) |
| Compatible Tube Diameter | 17 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 in 17 mm PP tubes — use the vented position during CO₂ incubation for gas exchange, then switch to fully closed for transport or storage
- Centrifugation with pressure equalization — vented position allows pressure relief during centrifuge spins, reducing the risk of cap ejection or tube deformation
- Serology and agglutination panels — snap cap re-seals securely after reading so tubes can be returned to incubation
- Flow cytometry sample preparation — vented during antibody staining incubation steps, closed for instrument loading and aerosol containment
- Bulk tube assembly and replacement cap inventory — the 1000/Bag format supports high daily cap consumption in clinical and research settings
- General bench capping — instant snap-on closure for routine sample storage and handling in 17 mm PP round-bottom tubes
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 / chlorinated 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, ensuring low extractables for direct biological contact applications. The sterile 1000/Bag pack format supports both high-volume tube assembly lines and routine replacement cap inventory. LabSupplies.com is an authorized Caplugs® Evergreen dealer, shipping from USA inventory — typically same business day for stocking items — with tiered pricing available for institutional, clinical, and grant-funded laboratories.
Frequently Asked Questions
Are these caps sterile right out of the bag?
Yes — these caps are supplied sterile, making them suitable for cell culture, clinical sample handling, and other applications where contamination control is critical. Handle appropriately in a clean or aseptic environment after opening.
What does "two-position" mean in practice?
The cap snaps to two distinct positions. Position 1 is a vented, partially open state that allows gas exchange — useful during centrifugation or CO₂ incubation. Position 2 is fully closed for a secure seal during storage, transport, or whenever aerosol containment is required.
Will these caps fit any 17 mm test tube, or only PP tubes?
The snap mechanism is optimized for the dimensional tolerances of 17 mm OD polypropylene (PP) tubes. While the fit depends on the specific tube wall dimensions, they are not guaranteed to seat correctly on tubes made from other materials such as polystyrene or glass, which may have slightly different outer diameters or surface finishes.
Can these caps be autoclaved for re-sterilization?
LDPE has a relatively low melting point and is generally not recommended for autoclaving. These caps are supplied sterile for single-use or limited-use applications; re-sterilization by autoclave is not advised.