Most tube racks have a fixed footprint and tube capacity — you get what the mold provides and nothing more. The Globe Scientific TUFFBLOK is built differently: each individual 4-way PP rack unit interlocks physically with adjacent TUFFBLOK units to create a continuous, custom-sized rack array that expands in any direction across the bench. A single TUFFBLOK can be used standalone for small batch sets, or linked together into a 2×2, 3×4, or larger grid for high-throughput batch processing — all without tools, adapters, or additional hardware.
Available in Standard (456940, 4-way, PACK/5 at $73.10) and XL (456945, 4-way, PACK/5 at $148.30) sizes, in 7 colors — Blue, Natural, Green, Orange, Pink, Yellow, plus Assorted packs. Standard is designed for smaller-diameter tubes; XL accommodates larger tubes in the same link-together format. Both are autoclavable PP construction with heavy-duty chemical resistance.
Features and Benefits
4-Way Link-Together System: Each TUFFBLOK unit connects to adjacent units on all four sides, allowing any rectangular array size to be built up from individual units — expand the rack by adding units in any direction as batch size grows, or pull units off to downsize between runs without wasted rack space.
Standard and XL Sizes: Standard units for smaller-diameter tubes; XL units for larger tube diameters in the same modular link-together format. Both PACK/5 — a 5-pack provides immediate flexibility to build a 5-unit array or divide units across multiple workstations.
Heavy-Duty PP Construction: Thick-wall reinforced polypropylene provides substantially more rigidity than standard rack PP — the TUFFBLOK holds its shape under heavy tube loads and does not deform or warp in autoclave cycles, maintaining dimensional integrity for reliable tube retention across repeated use.
7 Colors Including Assorted: Blue, Natural, Green, Orange, Pink, Yellow, plus Assorted 5-packs — the assorted pack provides immediate color variety for establishing color-coded systems across multiple TUFFBLOK arrays by assay, priority, day, or group.
Autoclavable for Sterile Workflows: Both Standard and XL versions are autoclavable at 121°C — appropriate for tissue culture, sterile sample processing, and any workflow requiring equipment sterilization between experimental runs.
Specifications
| Property | Standard (456940) | XL (456945) |
|---|---|---|
| Pack Size | PACK/5 | PACK/5 |
| Price (PACK/5) | $73.10 | $148.30 |
| Material | Reinforced Polypropylene (PP) | |
| Link System | 4-Way — connects to adjacent TUFFBLOK units on all four sides | |
| Autoclavable | Yes | |
| Colors | Blue · Natural · Green · Orange · Pink · Yellow · Assorted | |
| Country of Origin | India | |
Laboratory Applications
High-throughput labs where batch size varies between runs — link TUFFBLOK units together into an array sized to the current batch, then detach and redistribute units for the next run without maintaining fixed-size racks for every possible batch volume
Bench organization systems requiring durable, long-service racks that survive daily heavy use, chemical exposure, and repeated autoclave cycles without warping or losing tube-retention geometry — heavy-duty PP construction exceeds standard rack durability
Color-coded multi-assay workflows using mixed-color TUFFBLOK arrays where differently colored units within a linked array differentiate specimen sub-groups, control positions, or priority tiers within a single large batch without physical separation between groups
Frequently Asked Questions
How many tubes does each TUFFBLOK unit hold?
Globe Scientific's documentation specifies tube counts per unit — verify the tube capacity per individual TUFFBLOK unit for your tube diameter from Globe Scientific's product specifications. A PACK/5 provides 5 individual units; each can be used standalone or linked together.
Standard vs XL — how do I choose?
Standard (456940) is designed for smaller-diameter tubes (test tubes, most centrifuge tubes); XL (456945) accommodates larger tube diameters. Check your most common tube OD against Globe Scientific's dimensional specifications for each size. Both use the same 4-way link system and are available in the same 7 colors.
Can Standard and XL units be linked together?
The Standard and XL TUFFBLOK units use the same 4-way link system; however, mixing sizes in a linked array may create dimensional mismatches at the linkage points. For the most stable linked arrays, use units from the same size family (all Standard or all XL).
Quality Assurance
Globe Scientific products are manufactured under strict ISO 9001:2015 certified quality systems. Designed to meet the demanding requirements of clinical and research laboratories, these products undergo rigorous inspection to ensure consistent performance and reliability.
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.