Indirect method for quantitative determination of bovine serum albumin and transferin by anodic stripping voltammetry with a rotating glassy carbon electrode

Bovine serum albumin determination based on methylene blue detection by photothermal lens spectroscopy

We report on a new sensitive method, for bovine serum albumin quantification, which is based on the use of methylene blue as a labelling agent combined with photothermal lens detection. In the presence of sodium dodecyl sulfate, methylene blue forms a dimer which can react with bovine serum albumin producing dedimerization. We found that, the photothermal signal decreases proportional to the concentration of bovine serum albumin added to the system composed by dodecyl sulfate and methylene blue. Therefore, the change of the signal intensity is linearly proportional to the concentration of bovine serum albumin. Under the optimized analytical conditions, used in this work, the photothermal signal is linearly dependent on the concentration of bovine serum albumin in the range of 0.5 × 10^-6-7.5 × 10^-5 gmL^-1 with a regression coefficient R² = 0.9954. The relative standard deviation for BSA determination at 3.5 × 10^-5 gmL^-1 (n = 5) is 2.3% and the achieved detection limit is 3.5 × 10^-7 gmL^-1.

Determination of human albumin in serum and urine samples by constant-energy synchronous fluorescence method

A sensitive spectrofluorimetric method using constant-energy synchronous fluorescence technique is proposed for the determination of human albumin without separation. In this method, no reagent was used for enhancement of the fluorescence signal of albumin in the solution. Effects of some parameters, such as energy difference between excitation and emission monochromators (ΔE), emission and excitation slit widths and scan rate of wavelength were studied and the optimum conditions were established. For this purpose factorial design and response surface method were employed for optimization of the effective parameters on the fluorescence signal. The results showed that the scan rate of the wavelength has no significant effect on the analytical signal. The calibration curve was linear in the range 0.1-220.0 µg mL(-1) of albumin with a detection limit of 7.0 × 10(-3)  µg mL(-1). The relative standard deviations (RSD) for six replicate measurements of albumin were calculated as 2.2%, 1.7% and 1.3% for 0.5, 10.0 and 100.0 µg mL(-1) albumin, respectively. Furthermore the proposed method has been employed for the determination of albumin in human serum and urine samples.

Levels of protein fractions in blood serum of periparturient goats

The aim of the study was to compare contents of individual protein fractions determined by electrophoresis in blood serum of healthy periparturient goats. Eight clinically healthy white shorthaired goats were examined. Blood samples of these goats were taken from v. jugularis three weeks and two weeks before the anticipated parturition, on the parturition day, 7 days after the parturition, and 28 days after the parturition. Individual protein fractions, albumins, α1-, α2-, β1-, β2- and γ-globulins were identified by electrophoretic analysis of blood serum. Percentage shares of individual protein fractions were converted from total protein values to g·l-1 values. The results indicated that individual serum protein fractions in periparturient goats showed significant dynamics of change. There were no significant differences between samples taken before the parturition and on the parturition day (except for the increase of β2 from 2.5 ± 0.3 g·l-1 observed 3 weeks before the parturition to 3.2 ± 0.4 g·l-1 measured 2 weeks before the parturition, and the decrease of γG levels from 9.5 ± 2.6 g·l-1 observed three weeks before the parturition to 8.1 ± 1.7 g·l-1 found on the parturition day), yet most indicators measured after the parturition were significantly higher (p < 0.05) than on the parturition day (values in g·l-1 observed on the parturition day versus values measured 28 days after the parturition: total protein 60.6 ± 4.3 vs. 71.3 ± 2.4, albumins 37.4 ± 2.9 vs. 42.7 ± 1.0, α2 3.4 ± 0.5 vs. 4.1 ± 0.8, β1 5.6 ± 0.5 vs. 6.3 ± 0.9, γG 8.1 ± 1.7 vs. 12.3 ± 1.9). The results bring new knowledge on the values of individual fractions of serum proteins in healthy goats, which is necessary for diagnostic interpretation of pathological findings in animals and also for experimental studies.