12 mm Test Tube Stoppers — LDPE, Lavender, BD® Vacutainer-Compatible | 300-2912-L20
These lavender low-density polyethylene (LDPE) stopper caps fit standard 12 mm OD test tubes — including 12 × 75 mm and 12 × 100 mm glass and polystyrene culture tubes — and are compatible with BD® Vacutainer and common polypropylene clinical tube formats used in hematology, molecular, and clinical chemistry workflows. The plug-in friction-fit design seats securely for repeated insertion and removal cycles, and the lavender color mirrors the CLSI H3 convention for EDTA anticoagulant tubes, making these stoppers the natural post-collection closure choice for CBC, HbA1c, and molecular specimen management. Supplied non-sterile in 1000/Bag, part number 300-2912-L20 is well suited to high-volume tube capping programs across clinical, research, and microbiology settings.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 300-2912-L20 |
| Tube OD | 12 mm |
| Cap Style | Stopper — plug-in friction fit |
| Material | Low-Density Polyethylene (LDPE) |
| Color | Lavender |
| Color Convention | CLSI H3 lavender-top EDTA anticoagulant tube convention |
| Compatible Tube Formats | 12 × 75 mm and 12 × 100 mm glass and PS culture tubes; BD® Vacutainer-compatible sizes; common PP clinical tube formats |
| Temperature Range | −20°C to +60°C |
| Sterility | Non-Sterile |
| Pack Size | 1000/Bag |
| BPA / Phthalates | BPA-free; no phthalate plasticizers |
| Country of Origin | USA |
Applications
- Hematology & molecular specimen closure: Post-collection capping of EDTA blood tubes (CBC, HbA1c, molecular diagnostics) using the CLSI-convention lavender color for immediate visual identification
- Microbiology culture tube capping: Sealing TSB, BHI, LB broth, and general culture tubes during 37°C incubation — LDPE retains its flex and seal engagement at incubation temperatures
- Refrigerated and frozen specimen archiving: Preventing evaporation and cross-contamination during extended cold storage of serum, plasma, and urine; LDPE remains flexible and accessible at −20°C
- Color-coded tube routing systems: Designating EDTA specimen batches in laboratory color-coding protocols aligned to CLSI conventions
- Cell culture capping: Closure of suspension culture and virus propagation tubes while the flexible stopper allows managed gas exchange
- Pneumatic tube transport: LDPE friction retention resists the acceleration forces of clinical pneumatic transport systems, keeping tubes sealed during transit
Compatibility
These stoppers are designed to fit 12 mm OD test tubes across the most common clinical and laboratory formats, including standard 12 × 75 mm and 12 × 100 mm glass and polystyrene culture tubes and BD® Vacutainer-compatible collection tube diameters. The 12 mm OD is the broadest compatibility size in the Caplugs® Evergreen stopper series, making these caps appropriate for general clinical chemistry, hematology, and microbiology tube formats alike. Because tube wall thickness and rim geometry can vary by manufacturer, we recommend confirming fit against your specific tube lot before deploying in high-volume production workflows.
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers / saline | Excellent |
| Serum, plasma, whole blood | Excellent |
| Urine | Excellent |
| Microbiology broth media (TSB, BHI, LB) | Excellent |
| Dilute acids and bases | Good |
| Ethanol (<70%) | Good — short-term contact |
| Concentrated aromatic / chlorinated solvents | Not recommended |
| Temperature: −20°C frozen storage | Compatible — LDPE remains flexible |
| Temperature: 37°C incubation | Compatible — seal engagement retained |
Quality & Procurement
Made in USA, these Caplugs® Evergreen stoppers are produced from BPA-free, phthalate-free LDPE resin under ISO 9001 quality management practices. LabSupplies.com is an authorized Caplugs® Evergreen dealer and ships from USA inventory, with same-business-day fulfillment available for stocking items. Tiered volume pricing is available for institutional purchasers, hospital systems, and grant-funded laboratories managing large specimen-tube programs.
Frequently Asked Questions
Are these stoppers sterile?
No — they are supplied non-sterile in 1000/Bag packaging, which is appropriate for the vast majority of clinical tube capping, culture tube, and archiving applications. If your workflow requires sterile closure, please contact us to discuss available options.
Will these fit BD® Vacutainer tubes?
Yes — the 12 mm OD size is compatible with BD® Vacutainer-compatible collection tube diameters as well as standard 12 × 75 mm and 12 × 100 mm glass and polystyrene culture tubes. Because tube wall dimensions can vary slightly by manufacturer and lot, verifying fit on a sample quantity before high-volume use is always a sound practice.
Why are these stoppers lavender?
Lavender is the CLSI H3 color convention for EDTA anticoagulant tubes — the standard tube type for CBC, HbA1c, and molecular testing. Using lavender stoppers for post-collection closure maintains the color-coding logic your staff already follows, reducing sorting errors in high-throughput specimen routing.
Can these stoppers be used during incubation or frozen storage?
Yes — the LDPE material remains flexible and retains friction-fit seal engagement across a temperature range of −20°C to +60°C, making it suitable for both 37°C microbiology incubation and −20°C frozen specimen archive access without the stopper becoming brittle or losing its seal.