Corning™ PYREX™ Disposable Flat Bottom Screw Cap Culture Tubes, Without Caps Corning™ PYREX™ Disposable Culture Tubes are made from borosilicate glass to minimize pH changes and reduce contamination. Featuring a flat bottom and threaded neck, these tubes are ideal for tissue culture and bacteriological applications. Sold without caps for flexible closure options. Product Details: Brand: Corning™ PYREX™ Product Type: Culture Tube Design Type: Threaded Closure Type: Not Included Thread Size: 18-415 Material: Borosilicate Glass Diameter: 20 mm Length: 145 mm Capacity: 29.5 mL Autoclavable: Yes Sterility: Non-sterile Disposable: Single-use Graduated: No Label Type: None Packaging: Bulk Application: Tissue culture, bacteriological work, leach-sensitive samples Key Features: Borosilicate glass construction reduces pH shifts and contamination Flat bottom design ensures stability and uniform heating Threaded neck compatible with standard screw caps (sold separately) Ideal for samples sensitive to leaching from plastic tubes Autoclavable for sterile laboratory workflows Suitable for tissue culture, microbiology, and general lab use