Phương pháp Lowry
- Thread starter devil0604
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Thạch Thành Trung
Senior Member
Hi, sorry vì tôi chưa hiểu ý bạn. Phương pháp lowry, dùng thuốc thử folin dựa vào sự tạo màu với tyrosin và tryptophan có trong dung dịch protein; Khác hoàn toàn với phương pháp Biure, sử dụng thuốc thử Biure, dựa vào sự tạo màu của phản ứng peptid với CuSO4 trong môi trường kiềm.
Về những phương pháp đinh lượng protein thì bầng tăng thao tác khá nhiều. Không biết bạn có nhầm lẫn gì ở đây không?
Về những phương pháp đinh lượng protein thì bầng tăng thao tác khá nhiều. Không biết bạn có nhầm lẫn gì ở đây không?
Nguyễn Duy Hưng
Senior Member
Phương pháp này dựa trên phản ứng Biuret đó bạn à
Waterborg (2002,7)
"The most accurate method of determining protein concentration is probably acid
hydrolysis followed by amino acid analysis. Most other methods are sensitive to the
amino acid composition of the protein, and absolute concentrations cannot be obtained
(1). The procedure of Lowry et al. (2) is no exception, but its sensitivity is moderately
constant from protein to protein, and it has been so widely used that Lowry protein
estimations are a completely acceptable alternative to a rigorous absolute determination
in almost all circumstances in which protein mixtures or crude extracts are
involved.
The method is based on both the Biuret reaction, in which the peptide bonds of
proteins react with copper under alkaline conditions to produce Cu+, which reacts with
the Folin reagent, and the Folin–Ciocalteau reaction, which is poorly understood but in
essence phosphomolybdotungstate is reduced to heteropolymolybdenum blue by the
copper-catalyzed oxidation of aromatic amino acids. The reactions result in a strong
blue color, which depends partly on the tyrosine and tryptophan content. The method is
sensitive down to about 0.01 mg of protein/mL, and is best used on solutions with
concentrations in the range 0.01–1.0 mg/mL of protein"
Waterborg (2002,7)
"The most accurate method of determining protein concentration is probably acid
hydrolysis followed by amino acid analysis. Most other methods are sensitive to the
amino acid composition of the protein, and absolute concentrations cannot be obtained
(1). The procedure of Lowry et al. (2) is no exception, but its sensitivity is moderately
constant from protein to protein, and it has been so widely used that Lowry protein
estimations are a completely acceptable alternative to a rigorous absolute determination
in almost all circumstances in which protein mixtures or crude extracts are
involved.
The method is based on both the Biuret reaction, in which the peptide bonds of
proteins react with copper under alkaline conditions to produce Cu+, which reacts with
the Folin reagent, and the Folin–Ciocalteau reaction, which is poorly understood but in
essence phosphomolybdotungstate is reduced to heteropolymolybdenum blue by the
copper-catalyzed oxidation of aromatic amino acids. The reactions result in a strong
blue color, which depends partly on the tyrosine and tryptophan content. The method is
sensitive down to about 0.01 mg of protein/mL, and is best used on solutions with
concentrations in the range 0.01–1.0 mg/mL of protein"
bosdomesticus
Junior Member
Trung thuộc bài ghê ta, mà Trung nói đúng đó bạn devil0604
sinhviennam3
Junior Member
thank nguyễn duy hưng nha,đang tìm cái phương pháp này mún chít lum
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