19 mL Round Bottom Test Tubes with Natural Screw Caps — Polystyrene, Sterile, 16 × 125 mm (222-2089-05I)
These 19 mL polystyrene round bottom test tubes ship individually packed and pre-sterilized, making them ready for immediate use in flow cytometry, cell sorting, and clinical sample preparation workflows. Measuring 16 × 125 mm, the round bottom geometry concentrates cell pellets and precipitates at the tube base for efficient resuspension after centrifugation, while the natural screw cap delivers a threaded, leak-resistant closure superior to snap-cap formats for large-volume specimen handling and transport.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 222-2089-05I |
| Volume | 19 mL |
| Dimensions | 16 × 125 mm |
| Bottom Style | Round Bottom |
| Cap Style | Natural Screw Cap |
| Material | Polystyrene (PS) |
| Color | Natural |
| Sterility | Sterile |
| Pack Size | 1 / Individually Packed |
| BPA / Phthalate Free | Yes |
| Country of Origin | USA |
Applications
- Flow cytometry and FACS analysis — round bottom PS is the standard tube format for most cytometer sample probes
- Immunofluorescence staining — optical clarity of polystyrene supports visual and instrument-based inspection of fluorescent samples
- Cell sorting and pellet concentration — round bottom geometry focuses pellets tightly at the tube base for clean aspiration after centrifugation
- Hematology sample preparation — 19 mL capacity and 16 × 125 mm dimensions suit standard hematology workflows
- Serological testing and agglutination assays — round bottom format facilitates reading of agglutination reactions
- Specimen collection and transport — threaded screw cap provides secure, leak-resistant containment during handling and transit
- General laboratory sample storage — individual sterile packaging ensures integrity from receipt through point-of-use
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers / saline | Excellent |
| Dilute acids | Good |
| Dilute bases | Good |
| Methanol | Good — short-term contact |
| Isopropanol | Good — short-term contact |
| Acetonitrile | Good — short-term contact |
| Aromatic / chlorinated solvents | Not recommended |
| Acetone | Not recommended |
| Autoclave | Not compatible — PS is not autoclavable |
Quality & Procurement
Made in USA, these Caplugs® Evergreen tubes are produced from virgin-grade, FDA-registered polystyrene resin that is BPA-free and phthalate-free, under ISO-certified quality management with lot-level traceability to support CAP, CLIA, and ISO 15189 documentation requirements. Individual sterile packaging maintains integrity from the manufacturing line through the point of use, eliminating the need for pre-use sterilization steps. LabSupplies.com is an authorized Caplugs® Evergreen dealer shipping from USA inventory, with volume and institutional pricing available for high-throughput clinical and research laboratories.
Frequently Asked Questions
Are these tubes sterile out of the package?
Yes — each tube and cap is individually packed and supplied sterile. The sealed packaging maintains that sterility from manufacturing through point-of-use, so no pre-use sterilization step is required.
Are these tubes compatible with standard flow cytometers?
A 16 × 125 mm round bottom polystyrene tube is the widely accepted format for most flow cytometry and FACS platforms. Verify your instrument's sample tube specifications before use, as some analyzers specify a particular outer diameter or wall thickness.
Can these tubes be autoclaved for reuse?
No — polystyrene is not autoclavable and will deform under steam sterilization conditions. These tubes are designed for single-use applications.
What is the difference between a screw cap and a snap cap for this tube format?
The threaded natural screw cap on these tubes creates a more secure, leak-resistant closure than a snap cap, which is particularly important during specimen transport, centrifugation, or any application where tube orientation may change. Snap caps are typically used for quick-access workflows where repeated opening is required.