4 mL Sample Cup Caps, Flat Top, LDPE, Blue — Cobas® Compatible Sealed Closure (300-1006-B20)
These blue Low-Density Polyethylene (LDPE) flat top caps provide a complete sealed closure for Caplugs® Evergreen 4 mL round-bottom and flat-bottom sample cups used in urinalysis, clinical chemistry, and serology workflows. Supplied non-sterile in 1000/Bag, part number 300-1006-B20 snaps onto the sample cup rim with positive retention to prevent evaporation during refrigerated storage, pneumatic tube transport, and pre-analytical staging. The blue color supports color-coded specimen routing — widely adopted in clinical laboratories to designate urine specimens and distinguish them from serum (red) and general-purpose (natural) cup batches on the processing bench and in auto-analyzer loading racks.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 300-1006-B20 |
| Cap Type | Flat Top |
| Material | Low-Density Polyethylene (LDPE) |
| Color | Blue |
| Cup Compatibility | Caplugs® Evergreen 4 mL round-bottom and flat-bottom sample cups |
| Probe Access | No — cap must be removed before probe aspiration |
| Sealing | Full sealed closure |
| Sterility | Non-Sterile |
| Pack Size | 1000/Bag |
| BPA / Phthalates | BPA-free; no phthalate plasticizers |
| Country of Origin | USA (California) |
Applications
- Urinalysis: sealing random urine sample cups during centrifugation and pre-analyzer staging in high-volume clinical labs
- Serum and plasma storage: preventing evaporation of primary tube-derived aliquots during refrigerated holding
- Auto-analyzer workflows: capped sample cup staging before aspiration on discrete analyzers such as Cobas® and AU-series platforms
- Pneumatic tube transport: snap-on retention maintains sealed closure under transport pressure and vibration
- Color-coded specimen routing: blue caps enable visual differentiation of urine batches from serum (red) and general-purpose (natural) cups on the processing bench
- Frozen specimen storage: LDPE flexibility prevents cap fracture through repeated snap-on/snap-off cycles at −20 °C
Compatibility
These flat top caps are designed to fit the Caplugs® Evergreen 4 mL sample cup family (127-0017 series), which is widely used with discrete auto-analyzers including the Cobas® and AU-series platforms. Because the cap must be removed before probe aspiration, these closures are best suited to workflows where cups are uncapped at the instrument or de-capped in batches prior to loading. Laboratories that require probe pierce-through-cap access should consider the perforated top cap format (300-1999-020). The same flat top LDPE cap geometry is available in Natural (300-1006-020) and Red (300-1006-R20) for facilities that use a full three-color specimen-routing system.
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Urine, aqueous buffers, saline | Excellent |
| Serum, plasma, whole blood | Excellent |
| Dilute acids and bases | Good |
| Standard assay diluents and reagents | Good |
| Refrigerated storage (4 °C) | Excellent — retains snap-on flexibility |
| Frozen storage (−20 °C) | Good — LDPE flexibility resists fracture under repeated cycling |
| Concentrated organic solvents | Not recommended |
Quality & Procurement
Made in USA at Caplugs® Evergreen's California facility, these sample cup caps are produced from BPA-free, phthalate-free LDPE resin under ISO 9001 quality management. LDPE's inherent chemical inertness at clinical storage temperatures minimizes the risk of extractables leaching into specimen contents. LabSupplies.com is an authorized Caplugs® Evergreen dealer stocking 300-1006-B20 in USA inventory, with tiered pricing available for high-volume clinical programs, hospitals, and institutional procurement contracts.
Frequently Asked Questions
Can the analyzer probe aspirate directly through these caps?
No — these are flat top sealed closures that must be removed before probe aspiration. If your workflow requires pierce-through-cap access without removing the cap, see the perforated top cap format (300-1999-020).
Will these caps stay engaged during frozen storage at −20 °C?
Yes. LDPE remains flexible at sub-zero temperatures, so the caps retain positive snap-on engagement through repeated freeze-thaw cycles without the fracturing that can occur with more rigid plastics.
Are these caps sterile?
No — they are supplied non-sterile in 1000/Bag bulk packaging, which is appropriate for the clinical chemistry, urinalysis, and serology workflows for which they are designed.
Why blue? Can I get these in other colors?
Blue is a widely adopted clinical laboratory convention for designating urine specimens, enabling quick visual differentiation on the processing bench and in analyzer racks. The same flat top LDPE cap is also available in Natural (300-1006-020) and Red (300-1006-R20) for facilities that use a full color-coded specimen-routing system.