Material: High borosilicate glass (heat resistance ranging from -30°C to 400°C) or standard soda-lime glass.
Shape: Cylindrical with a flat bottom or a conical bottom; the open end is typically rimmed.
Dimensions: Diameter 10–25 mm, length 75–200 mm, wall thickness 0.5–1.5 mm.
Characteristics: Transparent and corrosion-resistant; some test tubes feature graduated markings.
For routine maintenance, glass test tubes should be rinsed immediately with clean water after use. Stubborn stains may be removed by soaking in a dilute acid or base solution (concentration below 10%); avoid using metal brushes to prevent scratching. Periodic deep cleaning using an ultrasonic cleaner is recommended. For sterilization, autoclaving at 121°C for 20 minutes is appropriate.