19 mL Round Bottom Test Tubes with Natural Screw Caps — Polystyrene, Sterile, 25/Bag (222-2088-050)
These 19 mL round bottom polystyrene test tubes measure 16 × 125 mm and ship sterile in 25/Bag unassembled packaging, with tubes and natural screw caps packed separately for assembly immediately before use. The round bottom geometry concentrates cell pellets and precipitates at the tube base for efficient resuspension and aspiration after centrifugation, while the threaded natural screw cap delivers a leak-resistant closure suited to specimen transport and storage. Part number 222-2088-050 is a workhorse tube for flow cytometry, FACS analysis, immunofluorescence, and clinical sample preparation workflows.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 222-2088-050 |
| Volume | 19 mL |
| Dimensions | 16 × 125 mm |
| Bottom Style | Round Bottom |
| Cap Style | Natural Screw Cap |
| Assembly | Unassembled (tubes and caps packaged separately) |
| Material | Polystyrene (PS) |
| Color | Natural |
| Sterility | Sterile |
| Pack Size | 25/Bag |
| BPA / Phthalate Free | Yes |
| Country of Origin | USA |
Applications
- Flow cytometry and FACS analysis — the round bottom PS tube is the standard format for most cytometer sample introduction systems
- Immunofluorescence staining and cell sorting, where PS optical clarity allows visual inspection of sample color and turbidity
- Hematology sample preparation and serological / agglutination assays requiring a 16 × 125 mm round bottom format
- Specimen collection and transport where the threaded screw cap provides leak-resistant containment superior to snap-cap closures
- General laboratory sample handling, dilution series, and pellet-concentration workflows requiring an economical sterile tube
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 sterilization | Not compatible — PS is not autoclavable |
Quality & Procurement
Made in USA, these Caplugs® Evergreen tubes are manufactured from virgin-grade, FDA-registered polystyrene resin under ISO-certified quality management, and are BPA-free and phthalate-free. Sealed sterile packaging maintains integrity from receipt through point-of-use, and lot-level traceability supports CAP, CLIA, and ISO 15189 documentation requirements. LabSupplies.com is an authorized Caplugs® Evergreen dealer shipping from USA inventory, with tiered pricing available for high-volume institutional and grant-funded accounts.
Frequently Asked Questions
Are these tubes sterile out of the bag?
Yes — they are supplied sterile and individually protected within sealed packaging. Because the tubes and caps are packaged unassembled, simply assemble each tube immediately before use to maintain sterility at the point of use.
Why are the tubes and caps packaged separately?
The unassembled format lets users assemble each tube immediately before use, preserving the interior sterile environment and giving labs flexibility to inspect tubes and caps individually before committing them to a workflow.
Are these compatible with standard flow cytometers and FACS instruments?
Round bottom 16 × 125 mm polystyrene tubes in this size class are the widely accepted standard format for most flow cytometers and cell sorters. Confirm the tube outer diameter and length requirements specified in your instrument's operator manual before substituting OEM-supplied tubes.
Can these tubes be autoclaved or reused?
No — polystyrene is not autoclavable and these tubes are intended for single use. Attempting to autoclave PS tubes will cause deformation and loss of dimensional integrity.