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Assay | Detection Wavelength(s) (nm) * | Sensitivity and Effective Range | Mechanism of Action | Notes |
---|---|---|---|---|
Quant-iT protein assay (Q33210) Qubit protein assay (Q33211, Q33212) | 470/570 | Quasi-linear from 0.5 to 4 µg in a 200 µL assay volume, with a sample volume of 1–20 µL | Binds to detergent coating on proteins and hydrophobic regions of proteins; the unbound dye is nonfluorescent |
|
NanoOrange protein quantitation assay (N6666) | 470/570 | 10 ng/mL to 10 µg/mL | Binds to detergent coating on proteins and hydrophobic regions of proteins; the unbound dye is nonfluorescent |
|
CBQCA protein quantitation assay (C6667) | 450/550 | 10 ng/mL to 150 µg/mL | Reacts with primary amine groups on proteins in the presence of cyanide or thiols; the unreacted dye is nonfluorescent |
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EZQ protein quantitation assay (R33200) | 280 and 450/618 | 50 µg/mL to 5 mg/mL, with a sample volume of 1 µL | Binds electrostatically to basic amino acids, supplemented by additional hydrophobic interactions |
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Bradford assay (Coomassie brilliant blue) | 595 | 1 µg/mL to 1.5 mg/mL | Directly binds specific amino acids and protein tertiary structures; the dye's color changes from brown to blue |
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BCA method (bicinchoninic acid) | 562 | 0.5 µg/mL to 1.2 mg/mL | Cu2+ is reduced to Cu+ in the presence of proteins at high pH; the BCA reagent chelates Cu+ ions, forming purple-colored complexes |
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Lowry assay (biuret reagent plus Folin–Ciocalteu reagent) | 750 | 1 µg/mL to 1.5 mg/mL | Cu2+ is reduced to Cu+ in the presence of proteins at high pH; the biuret reagent chelates the Cu+ ion, then the Folin–Ciocalteu reagent enhances the blue color |
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Fluorescamine (F2332, F20261) | 390/475 | 0.3 µg/mL to 13 µg/mL | Reacts with primary amine groups on proteins; unbound dye is nonfluorescent |
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OPA (o-phthaldialdehyde) (P2331MP) | 340/455 | 0.2 µg/mL to 25 µg/mL | Reacts with primary amine groups on proteins in the presence of 2-mercaptoethanol; unbound dye is nonfluorescent |
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UV absorption | 280 | 10 µg/mL to 50 µg/mL or 50 µg/mL to 2 mg/mL | Peptide bond absorption; tryptophan and tyrosine absorption |
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* Excitation and emission wavelength maxima or absorption wavelength maximum, in nm. |
仅供科研使用,不可用于诊断目的。