High Temperature Resistant Borosilicate Glass Culture Tube Graduated Reusable Laboratory Tissue Culture Glass Test Tube OEM Custom Size. Premium 3.3 Borosilicate Material Low thermal expansion, strong anti-thermal shock, not easy to break during heating and cooling. High Temperature Sterilizable Support autoclaving and high-temperature disinfection, reusable for long-term use. Super Chemical Stability Resist most acids, alkalis and organic solvents, no reaction with culture medium. Smooth Inner & Outer Wall Reduce residue adhesion, easy to clean and dry. High Light Transmittance Crystal clear body, convenient for real-time observation of microbial and cell growth. Diversified Designs Round bottom / Flat bottom, screw cap / stopper types for selection. Strict Quality Control Uniform wall thickness, stable size, good sealing performance.