Resonance light scattering technique for the determination of protein with rutin and cetylpyridine bromide system

Study of the interaction of salmon sperm DNA with myricitrin-CPB based on the enhanced resonance light scattering signal and its potential application

A new assay of salmon sperm DNA at nanogram level was established based on enhanced resonance light scattering (RLS) signals of DNA with myricitrin and cetylpyridinium bromide dihydrate (CPB). The RLS spectral characteristics of DNA with myricitrin-CPB and the optimum conditions for determination of DNA samples have been studied. At pH 7.4, myricitrin-CPB could enhance the intensity of RLS signal of DNA at 468 nm. The enhanced RLS intensity was directly proportional to DNA concentration in the range of 0.076-4.2 μg mL(-1) with a good linear relationship (r=0.9944). The detection limit was 4.1 ng mL(-1). The synthetic samples were analyzed with satisfactory results that the recovery was 100.9-102.6% and RSD was 1.4-2.1%, which proved that the new method was reliable and applicable.

The analytical application and spectral investigation of DNA-CPB-emodin and sensitive determination of DNA by resonance Rayleigh light scattering technique

A new sensitive DNA probe containing cetylpyridinium bromide (CPB) and emodin (an effective component of Chinese herbal medicine) was developed using the resonance Rayleigh light scattering (RLS) technique. A novel assay was first developed to detect DNA at nanogram level based on the ternary system of DNA-CPB-emodin. The RLS signal of DNA was enhanced remarkably in the presence of emodin-CPB, and the enhanced RLS intensity at 340.0 nm was in direct proportion to DNA concentration in the range of 0.01-2.72 μg mL(-1) with a good linear relationship. The detection limit was 1.5 ng mL(-1). Three synthetic DNA samples were measured obtaining satisfactory results, the recovery was 97.6-107.3%.

A sensitive rutin assay using a simple probe manganese sulfate based on its novel resonance light scattering decrease phenomenon

A novel resonance light scattering (RLS) decrease method was developed to determine rutin with a simple probe manganese sulfate. At pH 7.5, the strong RLS intensity of manganese sulfate was remarkably decreased by the addition of rutin with the maximum peak located at 389.0 nm. Under the optimum conditions, a good linear relationship between the changes of RLS intensities of manganese sulfate with and without rutin and the concentrations of rutin was obtained over the range of 0.49-24.4 microg ml(-1) and a low detection limit (3sigma) 0.42 microg ml(-1) was achieved in the mean time. Based on this approach, a novel method for quantitative analysis of rutin is proposed in this paper. The method proposed was also applied successfully to the determination of rutin in commercial pharmaceutical preparations of compound rutin tablets and human urine samples. The assay is sensitive, rapid, inexpensive, practical and relatively free from interference generated by coexisting substances.

Determination of bovine serum albumin using resonance light scattering technique with sodium dodecylbenzene sulphonate-cetyltrimethylammonium bromide probe

In this paper, the anionic surfactant sodium dodecylbenzene sulphonate (SDBS) and cationic surfactant cetyltrimethylammonium bromide (CTMAB) were used as resonance light scattering (RLS) probe to determine bovine serum albumin (BSA). Based on the weak RLS intensity of SDBS-CTMAB probe and the enhancement of RLS intensity of BSA in the presence of the probe, a simple assay for BSA was developed. The experimental results showed that the formation of three component complex BSA-SDBS-CTMAB is the main reason for the enhancement of RLS intensity of BSA, in which SDBS as a bridge can interact with both BSA and CTMAB. The effects of pH value, incubation time, concentrations of SDBS and CTMAB on the enhanced RLS intensity of BSA were investigated. Under the optimum conditions, the enhanced RLS intensity is proportional to the concentration of BSA in the range from 2.5 x 10(-8) to 2.0 x 10(-6)mol L(-1). The detection limit is 9.7 x 10(-9) mol L(-1) for BSA. The study of foreign substance effect on the determination of BSA indicated that most of metal ions have little effect on the determination of BSA. The results of assay for BSA in synthetic samples were satisfactory.

Resonance light scattering technique for the determination of proteins with polymethacrylic acid (PMAA)

As a resonance light scattering (RLS) probe, the polyelectrolyte polymethacrylic acid (PMAA) was applied in this assay. The bovine serum albumin (BSA) and human serum albumin (HSA) were determined by the electrostatic interaction of PMAA and proteins. At pH 3.8 Na(2)HPO(4)-citric acid buffer solution, the RLS intensities of PMAA-BSA (HSA) system were greatly enhanced. The characteristic peaks were appeared at the wavelength 320, 546 and 594 nm. The optimization conditions of the reaction were also examined and selected. Under the selected conditions, the RLS intensities were proportional to the protein concentrations in the range of (0.0200-2.00) x 10(-6) mol/L for BSA and (0.0200-2.40) x 10(-6) mol/L for HSA. The influences of some foreign substances were also examined. The synthetic samples containing proteins and some real samples were analyzed and the results obtained were satisfactory.

A flow injection sampling resonance light scattering system for total protein determination in human serum

A novel flow injection method with resonance light scattering detection was developed for the determination of total protein concentrations. This method is based on the enhancement of RLS signals from Methyl Blue (MB) by protein. The enhanced RLS intensities at 333 nm, in a pH 4.1 acidic aqueous solution, were proportional to the protein concentration over the range 2.0-37.3 and 1.0-36.0 microg ml-1 for human serum albumin (HSA) and bovine serum albumin (BSA), respectively. The corresponding limits of detection (3sigma) of 45 ng ml-1 for HSA and 80 ng ml-1 for BSA were attained. The method was successfully applied to the quantification of total proteins in human serum samples, the maximum relative error is less than 1% and the recovery is between 98% and 102%. The sample throughput was 60 h-1.

Investigation on hyperin-cetyltrimethylammonium bromide-fibronectin system by resonance light-scattering technique

A simple, highly sensitive assay for fibronectin (Fn) was reported using resonance light-scattering (RLS) technique based on the enhanced RLS intensity of hyperin-cetyltrimethylammonium bromide (CTMAB)-Fn system. The interaction system of hyperin-CTMAB-Fn was investigated using spectral methods. Mechanistic investigations show that the main reason of the enhanced RLS intensity of Fn is the formation of three-component complex (hyperin-CTMAB-Fn), in which CTMAB acts as a bridge between hyperin and Fn. The effects of pH, surfactant, concentration of CTMAB and hyperin, incubation time and foreign substances on the enhancement of RLS intensity were studied. Under the optimum conditions, the enhancement of RLS intensity is in proportion to the concentration of Fn in the range of 1.9-248ng/ml. The synthetic samples containing Fn were analyzed and results obtained were satisfied.

Protein analysis with terbium (III) and sodium dodecyl sulphonate by a second-order scattering technique

This is the first report of terbium(III) as a probe of second-order scattering (SOS) for the determination of proteins in human serum at nanogram levels. A sensitive method has been developed using light scattering, based on the fact that the weak SOS of proteins can be enhanced in the presence of terbium(III) and sodium dodecyl sulphonate (SDS). With this method, 7.0 x 10(-9)-1.0 x 10(-5) g/mL human serum albumin (HSA) and 5.0 x 10(-9)-5.0 x 10(-6) g/mL gamma-globulin can be determined; the detection limits were 4.4 ng/mL for HSA and 3.1 ng/mL for gamma-globulin. The method has been applied to the detection of total proteins in human serum samples, and the results are consistent with those obtained by the Coomassie brilliant blue (CBB) G-250 assay.

Determination of human complement factor C4 using resonance light-scattering technique with sodium dodecylbenzene sulphonate probe

Based on the interaction between human complement factor C4 (human C4) and sodium dodecylbenzene sulphonate (SDBS) and the resonance light-scattering (RLS) technique, a highly sensitive assay for human C4 using resonance light-scattering technique was developed. At pH 2.8 Na2HPO4-citric acid buffer solution, the RLS intensities of SDBS system at 283, 503 and 600 nm were obviously enhanced in the presence of human C4. The effects of surfactant, pH, incubation time, concentration of SDBS and foreign substances on the enhanced RLS intensity of system were investigated. Under the optimum conditions, the enhanced RLS intensity is directly proportional to the concentration of human C4 in the range of (0.5-120)x10(-6)gl-1 and the linear regression equation was obtained with high correlation coefficient. This RLS technique was applied to the determination of human C4 in some synthetic samples with good recovery. Moreover, it was found that the electrostatic interaction is the main binding force between SDBS and human C4.