Protein Quantification Kit (Bradford Assay): Your Buyer's Guide for When BCA Isn't the Answer

The 30-Second Verdict

The Bradford assay isn't the newest method—but for certain samples, it's still the best. When your lysate contains reducing agents like DTT or β-mercaptoethanol, or when you need a rapid, one-reagent quantification with minimal hands-on time, Bradford outperforms BCA. Abbkine's Protein Quantification Kit (Bradford Assay, KTD3002) delivers the classic Coomassie Blue G-250 chemistry in an optimized format, with a working range of 50–1,000 µg/mL and a sensitivity of 25 µg/mL.

Pros

✅ Reducing-agent tolerant — Bradford is the method of choice when DTT or β-mercaptoethanol is present (BCA is compromised by these)[reference:21]

✅ Broad working range — 50–1,000 µg/mL (1–20 µg protein)[reference:22]

✅ Simple, rapid protocol — one reagent, short incubation, read at 595 nm

✅ Sensitivity — 25 µg/mL[reference:23]

✅ Coomassie Blue G-250 chemistry — the gold standard for Bradford-type assays[reference:24]

✅ No boiling or heating steps — ideal for heat-labile proteins

Cons

❌ Detergent sensitivity — requires SDS <0.1%, Triton X-100 <0.1%, Tween 20/60/80 <0.1%[reference:25]

❌ Non-linear standard curve — 标曲只能拟合为曲线形态，不支持做成直线（must be fitted as a curve, not a straight line）[reference:26]

❌ Narrower range than BCA (50–1,000 vs. 20–2,000 µg/mL)

❌ Not for clinical diagnosis (research use only)

Who Should Buy This Kit?

Ideal for:

• Labs whose samples contain DTT or β-mercaptoethanol—where BCA is unreliable
• Researchers quantifying heat-labile proteins that cannot tolerate BCA's 37–60°C incubation
• Labs needing a rapid, single-reagent workflow with minimal hands-on time
• Core facilities that want a complementary method to BCA for cross-validation
• Researchers working with samples that are detergent-free or can be diluted below the detergent tolerance threshold

Skip this if:

• Your samples contain SDS, Triton X-100, or Tween above 0.1% (use KTD3001 BCA instead)
• You need a linear standard curve for simplified calculations
• You require a range extending above 1,000 µg/mL

The Detergent Constraint: Plan Around It

The Bradford assay's Achilles' heel is detergent intolerance. If your samples are prepared in RIPA buffer (which typically contains 1% NP-40, 0.1% SDS, and 0.5% sodium deoxycholate), you cannot load them directly into a Bradford assay without dilution below the tolerance threshold[reference:27]. For these samples, BCA (KTD3001) is the pragmatic choice.

But if your samples are detergent-free—or if you can dilute them sufficiently—Bradford delivers a rapid, reducing-agent-tolerant alternative that complements BCA in any protein analysis toolbox.

The Bottom Line

For researchers whose samples contain reducing agents, who need a rapid single-reagent workflow, or who want a complementary method to BCA, KTD3002 delivers the classic Bradford performance with the convenience of a ready-to-use kit.

👉 Add Bradford to your quantification toolbox. View Product