- Made from Borosilicate 3.3 Glass.
- Conical Bottom
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CAT NO Capacity (mL) O.D. x Length(mm) Pack of 5 13×100 10 15×110 15 17×120 25 22×125 50 30×135
OVERVIEW:
The GWSI conical bottom centrifuge tube with graduation provides efficient pellet collection and accurate volume measurement in a versatile open-top design. Crafted from borosilicate 3.3 glass, it delivers high thermal shock resistance and chemical inertness for demanding separation workflows. The plain top allows users to select their preferred closure method—parafilm, aluminum foil, custom stoppers, or leave open for specific applications—while the conical base concentrates pellets for easy recovery and the graduated markings eliminate transfer steps.
HISTORY:
Plain centrifuge tubes without integrated closures emerged as laboratories recognized that different applications required different sealing approaches. Some workflows needed airtight seals for volatile solvents, others required gas exchange for aerobic cultures, and many needed no closure at all for open-system centrifugation. The open-top design provided maximum flexibility, allowing researchers to customize their closure method based on specific experimental requirements. This approach also reduced costs by eliminating unnecessary closure components when simple covers or no closure were sufficient.
APPLICATIONS:
– Pharmaceutical research labs — particle separation and precipitate collection where custom closure methods are preferred
– Biotech facilities — cell pelleting and subcellular fractionation with optional parafilm or foil covering
– Clinical laboratories — blood and urine sample processing where open or covered centrifugation is standard practice
– University teaching labs— demonstrating basic centrifugation techniques and separation principles in biochemistry courses
– College research groups — crystal harvesting and phase separation in synthetic chemistry with flexible closure options
– Industrial QC labs — sediment testing and particle analysis where open centrifugation is acceptable
– Environmental testing facilities — water and soil sample processing with customizable covering methods
MANUFACTURING PROCESS:
GWSI manufactures plain conical centrifuge tubes by melting borosilicate 3.3 glass at 1,650°C and forming the cylindrical body and conical bottom through precision automated molding or skilled hand-blowing for specialized sizes. The open top is fire-polished to create a smooth, uniform rim that accepts various closure methods without sharp edges. The entire tube undergoes controlled annealing to eliminate internal stress and ensure dimensional stability under centrifugal force and thermal cycling.
TESTING PROCESS:
Manual inspection verifies wall thickness uniformity, conical bottom geometry, rim smoothness, and graduation accuracy on every tube. Automated polarization stress testing then scans the glass for residual strain that could cause failure under centrifugal force. Sample tubes from each batch are spin-tested at rated speeds to verify structural integrity, and graduation marks are validated against certified volumetric standards to ensure measurement accuracy.
PRINTING PROCESS:
Volume graduation marks and identification areas are silkscreened onto the tube surface using ceramic glass inks formulated for borosilicate compatibility. The tubes enter high-temperature kilns where ceramic glass fusing permanently bonds the ink into the glass matrix. This creates durable, legible markings that resist solvents, acids, and repeated autoclaving—essential for tubes that undergo rigorous cleaning and sterilization between uses.
PACKAGING PROCESS:
Final sorting removes any tubes with wall defects, rim imperfections, conical bottom irregularities, or graduation errors. Approved tubes are individually wrapped or nested in compartmentalized trays to prevent contact damage during shipping. They’re packed in heavy-duty double-wall corrugated boxes with shock-absorbing dividers, suitable for domestic distribution or international export to research and clinical facilities.
MAINTENANCE & SAFETY:
– Clean immediately after use with appropriate solvents or detergents; the conical bottom requires thorough rinsing to remove all pellet residue
– Autoclave at 121°C / 15 psi; glass tubes are fully autoclavable and maintain integrity through repeated cycles
– Balance tubes carefully before centrifugation; unequal loading creates dangerous vibration and can cause tube failure
– Inspect before each use for cracks, chips, or stress marks, especially at the conical bottom where stress concentrates
– Cover with parafilm, foil, or appropriate stopper when working with volatile solvents or when aerosol containment is required
– Store upright in racks or boxes to prevent rolling and protect the conical bottom from impact damage
Manufactured by GWSI Glass Lab — Ambala, Haryana, India (The Science City)