4 mL Sample Cup Caps — Flat Top, LDPE, Red, 1000/Bag (300-1006-R20)
These red Low-Density Polyethylene (LDPE) flat top caps are designed to seal 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-R20 snaps onto the cup rim with positive retention, delivering a complete sealed closure that prevents evaporation during refrigerated staging, frozen storage, and pneumatic tube transport. The red color mirrors the CLSI H3/BD Vacutainer convention for serum tubes, enabling consistent visual identification of serum- and plasma-derived cups throughout the pre-analytical chain.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 300-1006-R20 |
| Cap Type | Flat Top |
| Material | Low-Density Polyethylene (LDPE) |
| Color | Red |
| Cup Compatibility | Caplugs® Evergreen 4 mL round-bottom and flat-bottom sample cups |
| Probe Access Without Removal | 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
- Sealing 4 mL sample cups containing serum or plasma during refrigerated staging and pre-analytical hold
- Capping urine sample cups prior to centrifugation and auto-analyzer loading in urinalysis workflows
- Preventing evaporation during pneumatic tube transport between collection and laboratory areas
- Color-coded specimen routing in high-volume clinical labs: red caps designate serum/plasma cups, enabling visual differentiation from blue (urine) or natural (general-use) capped cups
- Capped sample cup staging before aspiration on discrete analysis auto-analyzers (Cobas, AU series)
- Frozen cup storage at −20°C where flexible LDPE construction resists the brittleness that causes rigid caps to fracture under repeated snap-on/snap-off cycles
Compatibility
These flat top caps are engineered to fit Caplugs® Evergreen 4 mL round-bottom and flat-bottom sample cups, including the 127-0017 cup family, which are themselves widely used on discrete analysis auto-analyzers such as the Cobas and AU series. Because the cap must be removed before probe aspiration, they are best suited for capped-storage and transport steps in the pre-analytical workflow rather than on-analyzer piercing. Laboratories requiring probe access without cap removal should consider the perforated top cap format (300-1999-020). Also available in Natural (300-1006-020) and Blue (300-1006-B20) for color-coded specimen routing programs.
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Urine (aqueous) | Excellent |
| Serum / plasma | Excellent |
| Aqueous buffers and saline | Excellent |
| Dilute acids and bases | Good |
| Standard assay diluents (aqueous) | Excellent |
| Chlorinated / aromatic solvents | Not recommended |
| Autoclave sterilization | Not recommended |
Quality & Procurement
Made in USA (California), these Caplugs® Evergreen sample cup caps are produced from BPA-free, phthalate-free LDPE resin. LDPE's inherent flexibility ensures consistent snap-on retention and reliable sealed closure across the full temperature range of clinical sample handling — from room-temperature processing through 4°C refrigerated staging to −20°C frozen storage — without brittleness-related cap failure in high-cycle workflows. LabSupplies.com is an authorized Caplugs® Evergreen dealer and ships from USA inventory, with tiered pricing available for high-volume clinical programs, hospitals, and institutional procurement accounts.
Frequently Asked Questions
Can the analyzer probe aspirate through this cap without removing it?
No. The 300-1006-R20 is a fully sealed flat top cap that must be removed before probe aspiration. If your workflow requires pierce-in-place probe access, see the perforated top cap format (300-1999-020).
Why is this cap red, and does the color carry any clinical meaning?
Red mirrors the CLSI H3/BD Vacutainer convention for serum tubes, so red-capped sample cups are visually associated with serum- and plasma-derived specimens throughout the pre-analytical chain. This allows laboratory staff to route and identify specimen types by color without relying solely on labeling.
Will these caps hold securely during frozen storage at −20°C?
Yes. LDPE remains flexible at sub-zero temperatures, maintaining snap-on engagement without the brittleness that can cause rigid plastic caps to crack or disengage during frozen storage or repeated snap-on/snap-off cycles in high-volume clinical workflows.
Are these caps sterile, and are they BPA-free?
These caps are supplied non-sterile, which is standard for general clinical chemistry and urinalysis cup-capping applications. They are manufactured from BPA-free, phthalate-free LDPE resin.