- 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 25 10 15×110 25 15 17×120 25 25 22×125 12 50 30×135 12
OVERVIEW:
The GWSI conical bottom centrifuge tube with interchangeable stopper combines efficient pellet collection with versatile ground glass joint compatibility. Made from borosilicate 3.3 glass, it delivers high thermal shock resistance and chemical inertness for demanding separation and integration workflows. The precision-ground standard taper socket accepts interchangeable stoppers of various types—solid, hollow, or with instrument ports—while graduated markings enable accurate volume measurement directly in the tube.
HISTORY:
Traditional centrifuge tubes with ground glass joints emerged as researchers needed to integrate centrifugation steps into complex multi-component apparatus without sample transfer. Screw caps provided secure sealing but couldn’t connect to distillation, reflux, or inert atmosphere systems. The interchangeable stopper design solved this by allowing the same tube to function as a standalone centrifuge vessel or as a connected component in larger assemblies. This flexibility proved especially valuable in natural product isolation and synthetic chemistry where centrifugation was one step in a multi-stage workflow.
APPLICATIONS :
– Pharmaceutical research labs — cell pelleting and particle separation followed by direct connection to extraction or distillation apparatus
– Biotech facilities — subcellular fractionation with subsequent inert atmosphere handling using hollow stoppers and gas lines
– Natural product chemistry — precipitate collection and crystal harvesting with immediate solvent exchange through connected apparatus
– University teaching labs — demonstrating integrated separation techniques combining centrifugation with distillation and reflux
– College research groups— multi-step synthetic workflows where centrifugation is followed by heating, refluxing, or solvent addition
-Analytical laboratories — sample preparation requiring sealed centrifugation followed by connection to analytical instrumentation
– Process development labs — pilot-scale separations that integrate with downstream processing equipment
MANUFACTURING PROCESS :
GWSI produces conical centrifuge tubes with interchangeable stoppers by melting borosilicate 3.3 glass at 1,650°C and forming the cylindrical body, conical bottom, and ground glass socket through precision automated molding or skilled hand-blowing. The standard taper socket is ground and lapped to exact specifications for leak-tight engagement with matching stoppers. 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, socket taper accuracy, and graduation precision 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, socket fit is validated with master gauges, and graduation marks are checked against certified volumetric standards.
PRINTING PROCESS:
Volume graduation marks and joint size identification are screened 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 used in rigorous chemical workflows.
PACKAGING PROCESS :
Final sorting removes any tubes with wall defects, socket 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 facilities worldwide.
MAINTENANCE & SAFETY :
– Clean thoroughly after use with appropriate solvents or detergents; pay special attention to the conical bottom and ground glass socket
– Autoclave at 121°C / 15 psi with stopper removed or loosened to prevent pressure buildup; glass is fully autoclavable through repeated cycles
– Balance tubes carefully before centrifugation; unequal loading creates dangerous vibration and can cause catastrophic tube failure
– Inspect before each use for cracks, chips, or stress marks, especially at the conical bottom and socket junction where stress concentrates
– Grease the ground glass joint lightly when using solid stoppers for enhanced seal; avoid grease when connecting to apparatus requiring clean joints
– Store upright in racks with stoppers removed or separated to prevent cold-fusion of ground glass surfaces during prolonged storage
Manufactured by GWSI Glass Lab — Ambala, Haryana, India (The Science City)