5.0 mL Round-Bottom Sterile Test Tubes with Two-Position Snap Cap, 12 × 75 mm — PS, Natural, 500/Box (222-2036-05I)
These 5.0 mL polystyrene round-bottom test tubes measure 12 × 75 mm and arrive pre-assembled with a two-position snap cap, individually sterile-packed and ready for immediate use straight from the wrapper. Supplied 500 per box in the individually packed format, part number 222-2036-05I is the preferred choice for flow cytometry (FACS), tube serology, and immunophenotyping workflows where sterility assurance and single-step opening are non-negotiable. The optical clarity and low autofluorescence background of polystyrene make these tubes ideal for both fluorescence-based detection and visual agglutination reading.
Technical Specifications
| Specification | Value |
|---|---|
| Part Number (MPN) | 222-2036-05I |
| Capacity | 5.0 mL |
| Dimensions | 12 × 75 mm |
| Geometry | Round Bottom |
| Material | Polystyrene (PS) |
| Color | Natural (clear) |
| Cap / Closure | Two-position snap cap — pre-assembled |
| Sterility | Sterile — individually packed |
| Pack Size | 500/Box |
| BPA / Phthalate / Latex | BPA-Free, Phthalate-Free, Latex-Free |
| Country of Origin | USA |
Applications
- Flow cytometry (FACS): The 12 × 75 mm format fits all major flow cytometer tube holders; polystyrene's low autofluorescence minimizes background signal during fluorescence-based cell analysis.
- Cell sorting: The snap cap is removed for cell sorter nozzle access; the 5.0 mL capacity accommodates standard sample volumes with room for sheath fluid carry-over.
- Tube serology and blood bank testing: PS optical clarity enables direct visual reading of agglutination reactions — button, partial agglutinate, or dispersed cell patterns are easily distinguished against the clear tube wall.
- Immunophenotyping: The 5.0 mL working volume comfortably accommodates a 50–100 µL sample combined with antibody cocktails and wash reagents during lyse/wash protocols.
- Intracellular staining: Compatible with methanol-based and saponin-based fixation/permeabilization protocols commonly used for cytokine and transcription factor detection.
- Short-term cell culture and stimulation: The two-position snap cap provides a vented position for CO₂ exchange during incubation and a closed position for capped transport or centrifugation.
- Centrifugation wash steps: The round-bottom geometry forms a compact, uniform cell pellet; recommended for wash centrifugation up to 600 × g.
Compatibility
The 12 × 75 mm tube is the global standard for flow cytometry sample presentation and fits the tube holders of widely used platforms including the BD FACSCanto™, BD LSRFortessa™, Beckman Coulter CytoFLEX™, and Thermo Fisher Attune™ series, among others. These tubes are a BD®-compatible alternative, offering the same 12 × 75 mm footprint and round-bottom geometry specified by BD for routine FACS work. Labs currently sourcing BD-branded 12 × 75 mm tubes can substitute these directly without modifying instrument settings or sample-handling protocols — verify your specific instrument's tube-holder specification before transitioning from OEM supply at scale.
Chemical Resistance
| Reagent / Condition | Compatibility |
|---|---|
| Aqueous buffers (PBS, HBSS, saline) | Excellent |
| Dilute acids and bases | Good — short-term contact |
| Methanol (fixation protocols) | Compatible — short-term contact at standard fixation concentrations |
| Saponin-based permeabilization buffers | Compatible |
| Ethanol >70% | Not recommended — risk of crazing or dissolution |
| Acetone | Not recommended — PS dissolves |
| Chlorinated solvents (chloroform, DCM) | Not recommended — PS dissolves |
| Aromatic solvents (toluene, xylene) | Not recommended — PS dissolves |
| Autoclaving | Not recommended — PS is not autoclavable |
Quality & Procurement
Made in USA, these Caplugs® Evergreen test tubes are produced from BPA-free, phthalate-free, latex-free polystyrene resin under ISO 9001 quality management, and each tube is individually sterile-packed with its snap cap pre-assembled — eliminating handling steps and reducing contamination risk at the point of use. LabSupplies.com is an authorized dealer of Caplugs® Evergreen consumables and ships from USA inventory, with same-business-day dispatch on stocking items and volume pricing available for high-throughput clinical, blood bank, and research laboratory accounts.
Frequently Asked Questions
Are these tubes sterile out of the box?
Yes — each tube is individually sterile-packed with its snap cap pre-assembled. Simply open the individual wrapper and the tube is ready for immediate use without any additional assembly or surface decontamination step.
Will these tubes fit my BD FACSCanto or other major flow cytometer?
The 12 × 75 mm format is the industry-standard tube size for flow cytometry and is compatible with tube holders on the BD FACSCanto™, BD LSRFortessa™, Beckman Coulter CytoFLEX™, Thermo Fisher Attune™, and most other platforms that accept the standard 12 × 75 mm geometry. Always confirm your instrument's tube-holder specification before switching from your current supply.
How does the two-position snap cap work for cell culture?
The snap cap has two locking positions: a vented position that allows CO₂ and gas exchange during incubation, and a fully closed position for sealed transport or centrifugation. This makes the tubes suitable for short-term stimulation assays and culture steps that precede flow cytometric analysis.
Is polystyrene compatible with fixation and permeabilization reagents used in intracellular staining?
These PS tubes are compatible with methanol-based fixation and saponin-based permeabilization buffers at concentrations typically used in intracellular cytokine and transcription factor staining protocols. However, PS is not resistant to high-concentration ethanol, acetone, or chlorinated and aromatic solvents, so reagent compatibility should be confirmed for any non-standard fixation chemistry.