- Made from Borosilicate 3.3 Glass.
- Conical Bottom
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CAT NO Capacity (mL) Pack of 10 15 50
OVERVIEW:
The GWSI conical bottom centrifuge tube combines precision graduation with a tapered base designed for efficient pellet collection and easy resuspension. Crafted from borosilicate 3.3 glass, it delivers high thermal shock resistance and chemical inertness for demanding separation workflows. The secure screw cap maintains leak-tight sealing during high-speed centrifugation, while the graduated markings enable accurate volume measurement without transferring samples to separate vessels.
HISTORY:
Conical bottom centrifuge tubes emerged as cell biology and biochemistry research expanded in the mid-20th century, requiring efficient methods to separate and recover pelleted materials. Flat-bottom tubes made pellet resuspension difficult and sample recovery incomplete. The conical design concentrated pellets into a small, accessible area at the tube’s apex, dramatically improving recovery rates. Glass construction became the standard for applications requiring chemical resistance, autoclaving, and compatibility with organic solvents that would degrade plastic alternatives.
APPLICATIONS:
– Pharmaceutical research labs— cell pelleting, protein precipitation, and particle separation during drug discovery and formulation development
– Biotech facilities — bacterial cell harvesting, yeast collection, and subcellular fractionation in molecular biology workflows
– Clinical laboratories — blood component separation, urine sediment analysis, and clinical sample processing
– University teaching labs — demonstrating centrifugation principles and separation techniques in biochemistry and cell biology courses
– College research groups — isolating precipitates, collecting crystals, and separating phases in natural product chemistry and materials science
– Industrial QC labs — particle size analysis, sediment testing, and quality control separations
– Environmental testing facilities — water and soil sample processing for contaminant analysis
MANUFACTURING PROCESS:
GWSI manufactures 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 screw thread is molded or tooled into the tube opening to accept standard caps with secure, leak-tight engagement. The entire tube undergoes controlled annealing to eliminate internal stress and ensure dimensional stability, critical for withstanding high centrifugal forces without failure.
TESTING PROCESS:
Manual inspection verifies wall thickness uniformity, conical bottom geometry, screw thread quality, and graduation accuracy on every tube. Automated polarization stress testing then scans the glass for residual strain that could cause catastrophic 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, thread 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 with caps loosened to prevent pressure buildup; 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
– Tighten screw caps securely but avoid over-torquing, which can crack the glass threads
– 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)