Larger-diameter tubes — 20 to 30 mL culture tubes, Universal tubes, wide serology formats — have no natural home in most rack lines. The 13mm and 17mm racks are too narrow; the conical tube racks are the wrong shape. The Heathrow Scientific HS243071 Fold & Snap Tube Rack fills this gap with 40 wells at 21mm diameter, covering tubes from 5 to 30 mL that fall outside every other rack in the Fold & Snap line.
Like all Fold & Snap racks, it ships flat in a single polypropylene piece, assembles without tools in seconds, withstands autoclave cycles, and performs in water baths. Open well design ensures uniform incubation temperatures across all 40 positions. Available in Blue, White, Red, and Yellow for color-coded sample management.
Features and Benefits
21mm Wells - Widest Fold & Snap Format: Accommodates tubes from 5–30 mL with 21mm outer diameter — covers the large-diameter tube formats excluded by the 13mm and 17mm models.
Flat-Pack Storage and Shipping: Ships as a single flat sheet — minimal storage footprint before assembly. Fold along scored lines and snap into 40-well configuration in seconds.
Autoclavable Polypropylene: Withstands standard 121°C sterilization cycles — suitable for labs requiring sterile tube organization between experiments or users.
Water Bath Compatible: Stable base maintains all 40 tubes upright during submersible water bath incubations. Open wells allow uniform temperature distribution.
4 Colors for Sample Organization: Blue, White, Red, and Yellow allow color-coded assignment across experiments, sample types, or users in multi-project lab environments.
Compact 9.8 × 4.2 in Footprint: 40-place capacity in a bench-efficient profile — fits standard lab bench depths without overhanging edges.
Specifications
| Property | Value |
|---|---|
| SKU Series | HS243071B, HS243071W, HS243071R, HS243071Y |
| Brand | Heathrow Scientific |
| Material | Polypropylene |
| Number of Wells | 40 |
| Well Diameter | 21 mm |
| Compatible Tube Size | 5–30 mL |
| Dimensions (L x W x H) | 9.8 x 4.2 x 2.8 in (24.9 x 10.8 x 7.2 cm) |
| Quantity | 1 Each |
| Autoclavable | Yes |
| Colors Available | Blue, White, Red, Yellow |
| Weight | 0.35 lb (0.16 kg) |
| Country of Origin | China |
Choosing the Right Fold & Snap Size
| Model | Well Diameter | Tube Size | Capacity |
|---|---|---|---|
| HS243073 (13mm) | 13 mm | 5–10 mL | 90 wells |
| HS243077 (17mm) | 17 mm | 5–15 mL | 60 wells |
| HS243071 (21mm) | 21 mm | 5–30 mL | 40 wells |
Laboratory Applications
Large-diameter culture tube workflows using 20–25 mL Universal tubes or other wide-format glass or plastic labware not served by narrower rack formats
Water bath incubations requiring stable upright support for wide-diameter tubes across extended temperature-controlled protocols
Mixed tube-size labs needing autoclavable racks that cover the 21mm diameter range not addressed by other Fold & Snap models
Teaching and training labs requiring economical, color-coded tube racks that can be sterilized between student groups
Frequently Asked Questions
Will 15 mL Falcon-style conical tubes fit the 21mm rack?
Standard 15 mL conical tubes typically have a ~17mm outer diameter at the body, so they fit loosely in 21mm wells. For a snug, secure fit in 15 mL conical tubes, the HS24311 Peg Rack or HS24318 Pop-Up Rack (17mm wells) are better choices. The 21mm Fold & Snap is optimized for round-bottom tubes in the 21mm outer diameter range.
What types of 20–30 mL tubes fit the 21mm wells?
Standard 25 mL Universal tubes (21mm OD), wide serology tubes, and other round-bottom glass or plastic tubes with 20–21mm outer diameters. If you're unsure whether your specific tube fits, measure the outer diameter at the tube body — wells accommodate up to 21mm OD.
How does this compare to the 13mm and 17mm Fold & Snap models?
See the size comparison table above. The 21mm model trades higher capacity (40 vs 60 or 90 wells) for wider well diameter — use it when tube OD exceeds 17mm.
Is assembly permanent?
Yes. Once snapped together, the rack is a rigid structure and is not designed to re-collapse. The flat-pack format is for pre-assembly storage and shipping efficiency.
Quality Assurance
Heathrow Scientific manufactures this rack from virgin polypropylene for consistent structural integrity and chemical resistance. Each rack is tested to confirm stable snap-joint assembly and consistent 21mm well geometry across all 40 positions through autoclave and water bath cycling.
Academic and Institutional Pricing
LabSupplies.com offers tiered quantity pricing for academic and research institutions. As an authorized dealer, we ship directly from USA inventory.