How we measured protein binding

To quantify how much protein a tube holds onto, you need a protein you can count. We used FITC-labeled bovine serum albumin (BSA-FITC) — a fluorescent model protein — so that the amount of protein remaining in solution can be read directly as a fluorescence signal.

The method, in brief:

• Dissolve BSA-FITC in PBS at 1 µg/mL — deliberately dilute, because dilute is where wall binding hurts most.
• Add 200 µL to each tube, seal, and hold at room temperature, protected from light.
• At 0 h, 24 h, and 48 h, mix, sample 50 µL, and read fluorescence (excitation 485 nm / emission 535 nm).
• Calculate protein recovery = fluorescence remaining in solution ÷ starting fluorescence × 100%.

A higher recovery means less protein was lost to the tube wall. We ran three products side by side, in triplicate:

• CP — Biofargo Low Protein-Binding tube

• NC — a standard (untreated) tube

• E — a leading competitor's protein low-binding tube

The results

Two things stand out.

1. The low-binding surface clearly works. After 48 hours, the Biofargo tube retained ~80% of the protein in solution versus ~71% for a standard tube — roughly a 9-percentage-point rescue of sample that a standard tube would have lost to its walls. At 24 hours the gap is about 10 points (88.5% vs 78.7%).

2. It performs on par with — even slightly ahead of — the premium competitor. Against a leading brand's protein low-binding tube (E), Biofargo matched it at 24 h and came out marginally ahead at 48 h (80.0% vs 76.7%). Within the assay's variability, the two are equivalent — meaning you're not trading performance for price.

(Full raw fluorescence values, per-replicate data, and recovery curves are in our validation report — see below.)

What the numbers mean for your bench

• More usable sample. For a dilute or low-abundance protein, recovering ~80% instead of ~71% after two days of storage is the difference between a clean result and a repeat experiment.
• Better reproducibility. Consistent wall behavior means your replicates and standard curves line up — critical for ELISA, BCA/Bradford, Western blot, and quantitative mass spec.
• Confidence in dilute work. The assay was run at 1 µg/mL on purpose. If a tube protects protein there, it protects your real dilute samples too.

Why this earns your trust — and your order

Anyone can print "low-protein-binding" on a bag. What should actually move your purchasing decision is a vendor that:

1. States the mechanism — a hydrophilic surface treatment on high-purity, additive-free polypropylene (no slip agents or plasticizers to leach into your sample).
2. Publishes the method and the numbers, not just the claim.
3. Benchmarks honestly against the market leader — and matches it.
4. Will send you a sample to verify on your own bench.

That's the whole point of Biofargo: the same validated performance as the premium brands, without paying for the brand name.

Get the data — and the tubes

Want the full validation report? It includes the complete raw dataset, the recovery curves, and the method in detail. Request the validation report →

Want to see it in your own workflow? We'll send a free sample to test head-to-head against your current tubes. Request a sample →

🛒 Ready to switch?

Order the 1.5 mL Low Protein-Binding SnapLock Tube (Cat# 801168-S) → 

Clear polypropylene · rated to 14,000 × g · sterile · validated protein recovery.

Related reading: Why Do Proteins Stick to Plastic Tubes? · Protein Low-Binding vs. DNA Low-Binding Tubes — Which One Do You Need?