高级放射性衰变计算器
计算放射性核素的衰变过程和剩余活度。
Protein Concentration
8.60 ug/mL
Protein Concentration vs Absorbance at 595 nm
公式
## Bradford Protein Assay The Bradford assay uses Coomassie Brilliant Blue G-250 dye, which shifts from red to blue upon binding protein. Absorbance at 595 nm is proportional to protein concentration. ### Calculation **[Protein] = (A595 - b) / m × dilution factor** where m and b come from a standard curve using BSA or another reference protein. The Bradford assay is sensitive to 1-20 ug/mL but has protein-to-protein variation.
计算示例
A Bradford assay reads A595 = 0.45, standard curve: m = 0.05, b = 0.02, no dilution.
- 01[Protein] = (0.45 - 0.02) / 0.05 × 1
- 02[Protein] = 0.43 / 0.05 = 8.60 ug/mL
常见问题
What is the linear range of the Bradford assay?
Standard Bradford: 100-1500 ug/mL. Micro Bradford: 1-25 ug/mL. Above the linear range, the curve flattens and concentrations are underestimated. Always dilute high-concentration samples.
What interferes with the Bradford assay?
Detergents (SDS, Triton X-100), strong acids or bases, and high salt concentrations can interfere. Basic amino acids (arginine, lysine, histidine) contribute most to the color response.
How does Bradford compare to BCA and UV280?
Bradford is fast and tolerant of reducing agents but protein-variable. BCA is more consistent but incompatible with reducing agents. UV280 requires no reagents but needs pure protein with known extinction coefficient.
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