Most tube racks are designed for one tube diameter — changing tube size means changing racks. The Heathrow Scientific HS24330A Universal Tube Rack uses an adjustable slot design that accommodates 15 to 50 mL conical tubes in the same 12-position rack by sliding the slot width to match the tube diameter. No tool required — adjust the slot, load the tube. 12 positions with slots adjustable from 16 to 30 mm diameter. Purple/white polypropylene, 7.6 × 5.5 × 2 in footprint. Features and Benefits Adjustable 16–30 mm Slot Width: The well slots adjust to the tube diameter — covers both 15 mL (approximately 16 mm OD) and 50 mL (approximately 28–30 mm OD) conical tubes in the same rack without changing or converting the rack. 12 Well Positions: Sufficient capacity for a batch of samples without a footprint that dominates the bench. No-Tool Adjustment: Slot width adjusts by hand — takes seconds to reconfigure from 15 mL to 50 mL format. Polypropylene Construction: Chemical-resistant PP in purple/white color for easy identification among other rack types. 7.6 × 5.5 in Footprint: Compact footprint compatible with biosafety cabinet, benchtop, and cold room use. Specifications Property Value SKU HS24330A Tube Sizes 15 mL and 50 mL conical tubes Well Diameter Range 16–30 mm (adjustable) Number of Wells 12 Dimensions 7.6 × 5.5 × 2 in (19.4 × 14 × 5.1 cm) Material Polypropylene Color Purple/White Quantity 1 Each Laboratory Applications Mixed 15 mL and 50 mL tube workflows where a single rack that holds both sizes reduces the number of racks on the bench Cell culture media preparation where both 15 mL and 50 mL conicals are used in the same protocol step Teaching labs where tube size varies by exercise and a single universal rack serves multiple setups without rack inventory management Small labs where rack inventory is limited and a multi-size single rack reduces the required number of dedicated racks Frequently Asked Questions Can this rack hold tubes of different sizes simultaneously?The slot width adjusts globally — all 12 slots are set to the same width. To hold 15 mL and 50 mL tubes simultaneously in the same rack, the slot width would need to be at both diameters at once, which is not possible. Set the slot for one size at a time. For simultaneous multi-size holding, consider the Transformer Cube (HS23271A) or the 4-Way Rack (HS29022 series). What tubes have a 16–30 mm outer diameter?Standard 15 mL conical tubes are approximately 16–17 mm OD at the body. Standard 50 mL conical tubes are approximately 27–29 mm OD. Most tubes within these two standard sizes will fit. Verify your tube OD before ordering if fit is critical. Is this autoclavable?Not listed as autoclavable for HS24330A. For autoclavable tube rack options in 15/50 mL formats, see the Pop-Up Tube Rack Combo (HS24320B) or the Transformer Cube Rack (HS23271A). Quality Assurance Heathrow Scientific HS24330A Universal Tube Racks are manufactured from polypropylene with an adjustable slot mechanism designed for repeated repositioning without mechanism wear under normal lab use. Ordering Authorized dealer, ships from USA inventory. Serving academic, government, and research laboratories nationwide.