Screw Caps for 20 mL Vials / 30 mL Centrifuge Tubes — HDPE, Black, 1000/Bag (300-3532-Z20)
These replacement screw caps are molded from high-density polyethylene (HDPE) and sized to fit 20 mL vials and 30 mL centrifuge tubes, providing a secure, re-sealable closure for sample storage and processing. Supplied non-sterile in bulk (1000/Bag), the black color offers light-blocking utility for light-sensitive samples and convenient visual differentiation in multi-tube workflows. Part number 300-3532-Z20 is an economical stocking choice for labs that routinely cap large numbers of tubes.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 300-3532-Z20 |
| Fits | 20 mL Vials / 30 mL Centrifuge Tubes |
| Closure Type | Screw Cap |
| Material | High-Density Polyethylene (HDPE) |
| Color | Black |
| Sterility | Non-Sterile |
| Pack Size | 1000/Bag |
| Country of Origin | USA |
Applications
- Re-sealing 20 mL vials and 30 mL centrifuge tubes for sample storage
- Capping tubes containing light-sensitive reagents, specimens, or extracts where black closures help reduce photodegradation
- Color-coded tube identification in multi-sample or multi-study workflows
- Bulk re-capping applications in high-throughput clinical, environmental, or research laboratories
- Replacing damaged or missing caps on compatible vials and centrifuge tubes
Material & Chemical Resistance
High-density polyethylene offers broad general chemical resistance, including good compatibility with aqueous solutions, dilute acids and bases, and many common laboratory reagents. HDPE is a rigid, low-moisture-absorbing material well suited to liquid containment; however, it is not recommended for autoclaving and may be affected by prolonged exposure to strong oxidizing acids or halogenated solvents. These general properties make HDPE a reliable choice for diverse sample types in everyday lab use.
Quality & Procurement
Made in USA, Caplugs® Evergreen screw caps are produced under ISO 9001 quality management from BPA-free, phthalate-free, latex-free HDPE resin. LabSupplies.com is an authorized dealer and ships from USA inventory, typically same business day for stocking items, with tiered pricing available for institutional and grant-funded laboratories.
Frequently Asked Questions
Are these screw caps sterile?
No — they are supplied non-sterile in 1000/Bag bulk packaging, which is appropriate for general laboratory storage and non-sterility-critical applications.
Will the black color help protect light-sensitive samples?
The black HDPE construction blocks visible light at the cap, which can help reduce photodegradation of light-sensitive contents when used with an appropriately opaque tube. For complete light protection, the tube itself should also be opaque or amber.
Can these caps be autoclaved for sterilization before use?
HDPE is generally not recommended for autoclaving, as the high temperatures and steam pressure involved can deform or compromise the material. For sterile closure applications, consider using pre-sterilized caps or an alternative sterilization method compatible with polyethylene.