Total Protein Estimation Research Articles

Biochemical analysis of fat bodies of the popular silkworm breeds/hybrids and foundation crosses

The changes in the chemical composition of fat body reflect tissue specific changes in different developmental stages of the silkworm pupae. The data on the difference in the protein content of the fat body among the parents and single hybrid and foundation crosses revealed variations in protein content. In case of the total protein estimation, when males and females are being compared the females always exhibited higher protein content than males. The data of the difference in the carbohydrate content in the fat body among the males of single hybrid, foundation cross and that of the parents revealed that the concentration of glycogen in the fat body was higher in case of parents than that of hybrids and observed to be more in the females. Statistical analysis has shown significant results among the parents, FC and the hybrids for carbohydrate content in fat bodies. Accordingly, no major differences were noticed in the total lipid content between the breeds was observed even though small quantity of increase in lipid content was exhibited by the females. Since silkworm pupae mainly consisted of tricyclglycenol, phosphatidylethanolamine, and phosphati-dylcholine. Both of them contains approximately 40% of a-linolenic acid as the predominant fatty acid, silkworm pupae would be a good source of functional fatty acids in the diet.

Evaluation of the toxic potential of graphene copper nanocomposite (GCNC) in the third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg(9.).

Graphene, a two-dimensional carbon sheet with single-atom thickness, have attracted the scientific world for its potential applications in various field including the biomedical areas. In the present study the graphene copper nanocomposite (GCNC) was synthesized, characterized and evaluated for its toxic potential on third instar larvae of transgenic Drosophila melanogaster (hsp70-lacZ)Bg9. The synthesized GCNC was analyzed by X-ray diffraction (XRD), scanning/transmission electron microscopy (SEM/TEM), atomic force microscopy (AFM), and fourier transform infrared spectroscopy (FTIR). The GCNC in 0.1% DMSO was sonicated for 10 min and the final concentration of 0.033, 0.099, 0.199 and 3.996 µg/µl of diet were established. The third instar larvae were allowed to feed on it separately for 24 and 48 hrs. The hsp70 expression was measured by O-nitrophenyl-β-D-galactopyranoside assay, tissue damage by trypan blue exclusion test and β-galactosidase activity was monitored by in situ histochemical β-galactosidase staining. Oxidative stress was monitored by performing lipid peroxidation assay and total protein estimation. Ethidium bromide/acridine orange staining was performed on midgut cells for apoptotic index and the comet assay was performed for the DNA damage. The results of the present study showed that the exposure of 0.199 and 3.996 µg/µl of GCNC were toxic for 24 hr of exposure and for 48 hr of exposure: 0.099, 0.199 and 3.996 µg/µl of GCNC was toxic. The dose of 0.033 µg/µl of GCNC showed no toxic effects on its exposure to the third instar larvae for 24 hr as well as 48 hrs. This dose can be considered as No Observed Adverse Effect Level (NOAEL).

An Overview of the Kjeldahl Method of Nitrogen Determination. Part II. Sample Preparation, Working Scale, Instrumental Finish, and Quality Control

The Kjeldahl method was introduced in 1883 and consists of three main steps: sample digestion, distillation, and ammonia determination (titration being the primary method). The Kjeldahl method uses sulfuric acid, a variety of catalysts, and salts to convert organically bound nitrogen in samples to ammonium with its subsequent measurement (Sáez-Plaza et al., 2013). Today, this method is universally accepted and used in tens of thousands of laboratories throughout the world for nitrogen analysis in a wide variety of materials, such as foods, beverages, agricultural products, environmental samples, chemicals, biochemicals, and pharmaceuticals. However, successful analysis requires proper sampling and sample handling, which depend on the type of material. The Kjeldahl method has been validated and standardized for total (crude) protein estimation for a wide variety of food matrices, indirectly determined by their nitrogen content, and is the reference method adopted by many international organizations. The Kjeldahl procedure has several variants, based mainly on a sample size and apparatus required. A number of rapid and accurate instrumental methods have been gradually introduced that have some advantages compared to older techniques, if a large number of samples are to be run. Thus, extracted nitrogen from Kjeldahl can be determined by several other methods, i.e., spectrophotometric, potentiometric with ion selective electrode, FIA, ion chromatographic, and chemiluminescent methods. Quality control is essential for accurate and precise measurements of nitrogen by the Kjeldahl method. The importance of quality control in Kjeldahl analysis is stressed in this review. Despite some negative factors (i.e., it is hazardous, lengthy, and labor intensive), the Kjeldahl method and its variants with instrumental finish remain as accurate and reliable methods.

Cadmium Induced Toxicity and Antioxidant Activities in Labeo Rohita (Hamilton)

The present study was carried out to observe the toxicity of cadmium at various sublethal concentrations in common edible fish, Labeo rohita (rohu) during various exposure periods. Labeo rohita was exposed to sublethal concentrations of cadmium chloride that is 1.0 mg l -1 , 1.5 mg l -1 and 2.0 mg l -1 along with control for 24hr, 48hr, 72hr and 96hr. The fishes were sacrificed and muscle was collected for the estimation of total proteins, carbohydrate, lipids and antioxidant enzymes i.e. superoxide dismutase (SOD), lipid peroxidation (LPO) and catalase (CAT) activities. The maximum decrease in protein, carbohydrate and lipid content were found to be 40.44%, 32.17% , 33.12% at 96hr of exposure at 2 mg l -1 of CdCl2. Antioxidant enzyme activities were increased when fish exposed to sublethal concentration of cadmium chloride. The maximum increase in the level of catalase, lipid peroxidation, and superoxide dismutase was noted to be 141.2%, 94.6% and 71% respectively at 96hr exposure for 2.0 mg l -1 of Cdcl2.The results revealed that cadmium is highly toxic in muscle of Labeo rohita as there was a drastic reduction of biochemical parameters (carbohydrate, protein, lipids) and changes in the level of antioxidant enzymes activities.

Quantitative estimation of sodium, potassium and total protein in saliva of diabetic smokers and nonsmokers: A novel study

Aims:The aim of the study was to evaluate the difference in sodium, potassium, total protein in whole saliva in diabetic smokers, diabetic nonsmokers and healthy controls.Materials and Methods:Nonstimulated saliva samples were collected from a group of diabetic smokers, diabetic nonsmokers, and controls. Supernatant after centrifugation was used to determine the levels of sodium, potassium, and total protein by using semiautomatic analyzer.Results:There exists a statistical difference in the levels of potassium and total protein between diabetic smokers, nondiabetic smokers, and controls. Difference in the levels of sodium is only significant with nondiabetic smokers and controls.Conclusion:Diabetes mellitus is known to alter the composition of saliva. The purpose of this study was to estimate and compare the levels of salivary potassium, sodium, and total protein in smoker diabetic patients and nondiabetic smokers and controls, and to explore potential of salivary electrolytes [Na+, K+] and total proteins as markers. The estimated values of salivary constituents add to the data already recorded in Indian population. However, further studies using large samples are required to evaluate the findings in our study.

Total sialic acid, total protein and total sugar levels in serum and saliva of oral squamous cell carcinoma patients: A case control study.

Background:Detection of cancer at an early stage is of utmost importance to decrease the morbidity and mortality of the disease. Apart from the conventional biopsy, non-invasive methods like analysis of serum and saliva may provide cost-effective approach for screening a large population. Tumor markers are a major part of secondary prevention and thus, the detection of malignancies. The aim of this study was to evaluate total sialic acid (TSA), total protein and total sugar (TS) in serum and saliva of oral squamous cell carcinoma (OSCC) and controls to assess their role as a diagnostic marker.Materials and Methods:Unstimulated whole saliva and sera were collected from 40 squamous cell carcinoma patients and 20 controls. Serum and salivary TSA, total protein and TS estimation was carried out. This was correlated with clinical stages and histopathological grades of OSCC. The data obtained was analyzed statistically using Chi-square test, ANOVA and Student's t-test with SPSS statistical software.Results:A highly significant rise in the salivary sialic acid, serum sialic acid and serum protein was noted in OSCC subjects compared to controls. Salivary protein, serum and salivary sugar did not show any significance. Furthermore, serum and salivary sialic acid levels were found to be significantly increased with increasing level of histopathological grading.Conclusion:The present study showed a significant increase in serum sialic acid, salivary sialic acid and serum protein from control to OSCC and suggests that these markers may be reliable in diagnosis and predicting prognosis.

The Effect of Eclampsia on Gamma-Glutamyl Transferase Activity and some Bichemicals

The research included estimation of gamma-glutamyl transferase activity and total protein, albumin, globulin, heamoglubin, packed red cell volume ratio and electrolytes sodium, potassium in (30) pregnant women complication Eclampsia within gestational period first, second and third trimester, aging between (15-45) years, as well as in (30) pregnant women as control with similar age. The results showed significant decrease in the activity of gamma-glutamyl transferase in the second and third trimester, and significant decrease in concentration of total protein, albumin, haemoglubin, pack red cell volume and sodium at first, second and third trimester comparison to control group. According to correlation coefficient, the result showed that direct significant correlation between gamma-glutamyl transferase activity and protein concentration in the first trimester and direct significant correlation between gamma-glutamyl transferase activity and concentration of sodium level in the second trimester.

Hyperoxia‐induced Retinal Microvasculopathy Correlates with Lung Injury and Inflammation in Neonatal Mice

ObjectivePremature infants with respiratory failure require oxygen supplementation, which can destroy developing lungs and lead to acute lung injury (ALI). Continued oxygen use also damages retinal tissue by disrupting normal angiogenesis, leading to retinopathy of prematurity (ROP). Using a mouse model of oxygen‐induced retinopathy (OIR) and ALI, we assessed the correlation between retinal microvascular abnormalities in vivo and lung tissue injury ex vivo.MethodsNeonatal C57BL6/J mice were exposed to 75% oxygen from postnatal day 7 (P7) to P12 and then exposed to room air until P17. Fluorescein angiography (FA) images of the retinal vasculature were acquired in vivo. Bronchoalveolar lavage (BAL) was performed on the mice lung tissue ex vivo, followed by cytometry and protein estimation of the BAL fluid. The total cell count was used as a measure of lung inflammation; while total protein estimation was used to assess lung injury.ResultsIn vivo FA imaging of retinal vasculature revealed aberrant neovascularization and regions of capillary network loss in mice exposed to hyperoxia compared to room air exposed controls (Figure 1A). There was a 4‐fold increase in total inflammatory cells (Figure 1B) and a 3‐fold increase in protein levels in BAL fluids of hyperoxia‐exposed mice compared to room air controls.ConclusionsOur findings demonstrate a correlation between retinal microvasculopathy and lung tissue injury and inflammation in neonates, suggesting in vivo imaging of retinal microvasculature could be a potential biomarker for lung injury.Source of Research Support: R01 HL66109, R01 ES011863 and R01 EY017918

A Correlative Study on Hepatitis C Virus Load Determined by Real Time Polymerase Chain Reaction with Serum Biomarkers in Patients with Renal Disease

Purpose: To determine the Hepatitis C virus (HCV) load in peripheral blood specimens of patients with renal abnormality reporting to the nephrology unit and to correlate the viral load with different biomarkers in serum. Materials and Methods: Fifty peripheral blood specimens were obtained from patients reporting to the nephrology unit and these patients were categorized into three groups as Group I: Renal Transplant patients, Group II: Dialysis patients, Group III: Other patients. with elevated liver enzymes and renal pathology. Peripheral blood specimens collected from kidney transplant recipients (n = 11), dialysis (n=17) and others (n =22) were subjected to detection of antibodies to HCV, determination of viral load by Real Time PCR and biochemical profiling consisting of estimation of bilirubin, total protein, alanine aminotransferase, and alkaline phosphatase. Antibodies to HCV were detected by ELISCAN™ HCV and the viral load by using HCV RG RTPCR kit (QIAGEN, Hilden). Statistical analysis - T test and the logistic regression analysis assessing the correlation between viral load and serum bilirubin, Serum glutamate pyruvate transaminase (SGPT), Alkaline phosphatase, total protein were performed using SPSS software version 14.0 Results: Antibodies to HCV were detected by ELISA in 39 (78%) peripheral blood samples and genomic HCV was detected in 31 (62%) by RTPCR. In 8 (16%) patients, HCV antibodies only were detected and RTPCR did not reveal the presence of HCV in these specimens. Logistic regression analysis performed on biochemical parameters and viral load revealed correlation between alkaline phosphatase enzyme levels and viral load (Hosmer and Lemehow test P value< 0.05 statistically significant). Conclusion: Determination of viral load is a reliable diagnostic test in detection of HCV infection. Elevated levels of alkaline phosphatase enzyme could be associated with increased viral load. To the best of our knowledge, this finding is the first being reported in Indian literature.

Sub-lethal effect of chlorpyrifos on protein metabolism of the food fish Clarias batrachus and monitoring of recovery

The effect of sub-lethal concentrations of chlorpyrifos on protein metabolism in physiological important tissues, namely gills, kidney, liver, and muscle of the freshwater fish, Clarias batrachus, was studied. Fish were exposed to 1/20th and 1/10th of 96 h LC50 concentrations for 7, 14, 21, and 28 days. After 28 days of exposure, fish were released into fresh water and kept in the same for 21 days in order to study the recovery. Fish were sacrificed at the stipulated periods and gills, kidney, liver, and muscle tissues were used for the estimation of total protein, amino acids, ammonia, urea, glutamine, protease, transaminases, and phosphatases. Total protein, amino acid, and ammonia contents were decreased in all tissues for 28 days and recovery was observed during the recovery period. Urea and glutamine levels were elevated, except in kidneys, and recovered at the end of the recovery period. The activities of protease, alanine, and aspartate aminotransferases, and acid and alkaline phosphatases were elevated in the tissues for 28 days exposure at both concentrations. Recovery of these enzymes activities was noticed during depuration.

Effect of infrared radiation on the lens

Background:Infrared (IR) radiation is becoming more popular in industrial manufacturing processes and in many instruments used for diagnostic and therapeutic application to the human eye.Aim:The present study was designed to investigate the effect of IR radiation on rabbit’s crystalline lens and lens membrane.Materials and Methods:Fifteen New Zealand rabbits were used in the present work. The rabbits were classified into three groups; one of them served as control. The other two groups were exposed to IR radiation for 5 or 10 minutes. Animals from these two irradiated groups were subdivided into two subgroups; one of them was decapitated directly after IR exposure, while the other subgroup was decapitated 1 hour post exposure. IR was delivered from a General Electric Lamp model 250R 50/10, placed 20 cm from the rabbit and aimed at each eye. The activity of Na+-K+ ATPase was measured in the lens membrane. Soluble lens proteins were extracted and the following measurements were carried out: estimation of total soluble protein, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Fourier transform infrared (FTIR) spectroscopy. For comparison between multiple groups, analysis of variance was used with significance level set at P < 0.001.Results:The results indicated a change in the molecular weight of different lens crystalline accompanied with changes in protein backbone structure. These changes increased for the groups exposed to IR for 10 minutes. Moreover, the activity of Na+-K+ ATPase significantly decreased for all groups.Conclusions:The protein of eye lens is very sensitive to IR radiation which is hazardous and may lead to cataract.

PWE-002 Cell growth is impaired in a cellular model of non-alcoholic fatty liver disease, but is unaffected by simple steatosis

Introduction Non-alcoholic fatty liver disease (NAFLD) is an important cause of cirrhosis. Cirrhosis can be considered as a state where disordered growth leads to inadequate repair and a risk of malignancy. We sought to study the growth characteristics of C3A cells in an in vitro model of NAFLD. Methods C3A cells (well differentiated hepatoblastoma cells) were preconditioned for 72 h in control media, media containing oleate (which leads to steatosis, but not insulin resistance) or LPON media containing lactate (L), pyruvate (P), octanoate (O) and ammonia (N) (leading to steatosis, insulin resistance and increased reactive oxygen species). The cells were passaged and re-incubated in the appropriate media. Cells were harvested daily for cell counting and total protein estimation for 5 days. Cell cycle analysis and apoptosis estimation were performed on day 3. Results Growth curves were established, showing by both cell counting and protein estimation that growth was significantly reduced in the NAFLD model (p Cell cycle analysis showed that cells grown in LPON did not accumulate in G0/G1, but appeared to accumulate in S phase (Abstract 002 Figure 2). Cells grown in oleate cycled normally. There was an increase in apoptosis in both oleate and LPON groups (26.1 and 27.7% cells undergoing apoptosis, compared to 13.5% of control cells, p Conclusion NAFLD-induced cells showed significantly impaired growth compared with both control and simple steatotic cells in this model. This was not wholly attributable to an increase in apoptosis, as there was a similar increase in apoptosis with steatosis. While simple fat accumulation increased apoptosis, there was in addition, impairment of cell growth in our NAFLD model, which may be due to formation of reactive oxygen species, causing DNA damage and cell cycle arrest.

Enhanced phytase production through interspecific protoplast fusion of Aspergillus niger CFR 335 and Aspergillus ficuum SGA 01 auxotrophic mutants

Interspecific protoplast fusion between Aspergillus niger CFR 335 and Aspergillus ficuum SGA 01 auxotrophic mutant strains was carried out in the presence of PEG-3500 in order to enhance the phytase production. The protoplasting frequency found was 2.64 × 10 −3 and 3.72 × 10 −3 while the regeneration frequency was 32 × 10 −2 and 47 × 10 −2 in A. niger CFR 335 and A. ficuum SGA 01 respectively. Fusion frequency of 90 × 10 −2 was obtained when equal numbers of two protoplasts were induced to fuse. Sixteen stable hybrids were characterized for phytase production, their biomass and DNA contents. The hybrid biomasses were subjected to proximate analysis such as estimation of total sugars, proteins, total lipids and ash. H1 was found promising with high stability and delayed sporulation with the onset after 10 days of incubation while the maximum enzyme production of 126.2 U/gds was attained by 6–7 days, in solid-state fermentation medium. As there are no such studies reported till date, the present work opens a new area in phytase research in developing stable hybrids with desirable characteristics to meet present market demand for the enzyme.

Estimation of salivary amylase and total proteins in leukemia patients and its correlation with clinical feature and radiographic finding

Leukemia is a fatal disease. The oral manifestations of the leukemias occur early in the course of the disease and these oral features can at times act as a diagnostic indicator. Saliva has been used as a diagnostic aid in a number of systemic diseases. In our study, samples of unstimulated saliva of 30 leukemia patients who were not on chemotherapy were collected and analyzed for salivary amylase and total protein. The oral manifestations and radiographic changes (OPG) were recorded. The correlation between the oral manifestations and the salivary components (salivary amylase and total protein) was assessed for prognostic significance. In the present study when the mean values of salivary amylase (1280±754 U/ml) and total protein (647.2±320.7 mg%) were compared with that in control subjects. There was a statistically significant difference for amylase levels (P<.05). On intraoral examination the study subjects showed pallor, gingivitis, gingival enlargement, petechiae, and ecchymosis. On the OPG, the radiographic features included generalized rarefaction of bone (20%), thinning of lamina dura (3.4%), generalized alveolar crest bone resorption (30%), thinning of walls of alveolar crypts (6.7%), besides others, e.g., periapical abscess (10%). The saliva of leukemic patients demonstrated obvious changes in composition. A rise in salivary amylase and total protein levels was evident, with the increase in amylase levels being statistically significant.

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Use of Natural Coagulants of Plant Origin in Production of Soycurd (Tofu)

Tofu – Soycurd, is one of the important non-fermented soybean products, which has been widely used in a variety of dishes by oriental people for many centuries. Normally in the preparation of Tofu, synthetic coagulants such as calcium sulphate, magnesium chloride, Glucono-?-lactone, etc., are used. These coagulants are not readily available sometimes for use in the household and not available easily in the rural areas. Hence, an attempt was made to use natural coagulants of plant origin (Citrus lemon, Garcinia indica, Tamarindus indica, Averrhoa carambola, Averrhoa bilumbi, Phyllanthus distichus, Tamarindus indica flower extract, Hibiscus canabinus and Passiflora edulis) in preparation of Tofu. Yield, texture, proximate composition and sensory quality of Tofu prepared using natural coagulants were analyzed and a comparative evaluation was made between Tofu obtained from synthetic coagulants. Results showed that use of natural coagulants in preparation of Tofu increased the yield (24.5g/100 ml of soymilk). Total crude protein estimation revealed that the protein content in Tofu prepared using natural coagulants was comparatively higher than the synthetic coagulants (61.4% on dry weight basis). Texture analysis results of Tofu prepared using different coagulants showed that Garcinia indica extract produced Tofu with hard texture, more cohesiveness and chewiness compare to other coagulants followed by Calcium sulfate and Tamrindus indica. Sensory analysis of Tofu showed Citrus lemon extract produced best Tofu with higher overall quality in terms of appearance, texture, taste, flavor and color followed by Tamarindus indica.

Serum total proteins and serum total cholesterol levels in Gaolao Cattle

The healthy female Gaolao cattle were selected and divided in three groups of ten animals each with reference to age. The blood samples were processed for clear serum collection and estimation of serum total proteins, albumin, globulin, albumin and globulin ratio and serum total cholesterol. It is reported that female calves had low total proteins, albumin and globulin than the adult cows.

Modulation of the Glycemic Response Using Insulin Attenuates the Pulmonary Response in an Animal Trauma Model

Hyperglycemia has been shown to be an independent prognostic indicator of poor outcome in the traumatized patient. The role of insulin and the prevention of hyperglycemia in the trauma patient have as yet not been fully explored. We hypothesized that the systemic inflammatory response to trauma could be modified by modulating the glycemic response to trauma using insulin. A rodent model of end- organ (lung) injury in trauma was chosen. Two groups underwent bilateral femur fracture and 15% blood loss. The third group was anesthetized only. The treatment group immediately received subcutaneous insulin according to a sliding scale. The control groups received normal saline subcutaneously. The animals were maintained under anesthesia for 4 hours from injury. Blood samples were then taken. Bronchoalveolar lavage was performed for neutrophil content and total protein estimation. The left lower lobe was harvested for wet:dry lung weight ratios as a measure of end-organ tissue edema. Measures of end-organ injury, wet:dry lung weight ratios, and bronchoalveolar lavage neutrophil content were significantly reduced in the insulin-treated animals compared with in the controls (p < 0.05). Neutrophil respiratory burst activity was increased in insulin-treated animals compared with in controls (p < 0.05). Insulin reduces leukocyte lung sequestration and end-organ (lung) edema, indicating an endothelial protective effect in this injured-animal model without attenuating neutrophil function. This work confirms that modifying the glycemic response to trauma using insulin may have a role in reducing adult respiratory distress syndrome rates in injured patients and thereby lead to improved outcomes.

Spot morning urine protein creatinine ratio and 24 hour urinary total protein excretion rate

Proteinuria helps to establish the diagnosis of most renal diseases and also to predict the outcome of such diseases. Proteinuria is biochemically represented by measuring the protein concentration in timed collection of 24 hour urine. But, 24-hour timed urine collection is time consuming, cumbersome and often unreliable due to collection errors and also results in undue delay on diagnostic process. An alternate approach avoiding arduous and inaccurate timed urine collection can be the measurement of protein creatinine ratio in spot morning urine. This study was aimed to evaluate whether the spot morning urine protein creatinine ratio can be a reliable alternative to 24-hour urinary total protein (UTP) estimation. The study was carried out in the department of Biochemistry, Bangabandhu Sheikh Mujib Medical University, Dhaka on 50 (fifty) non-diabetic Chronic Renal Disease (CRD) patients with an age ranging from 18 -70 years. The study subjects were grouped into mild, moderate and severe CRD on the basis of GFR. Urinary protein and creatinine concentrations were measured in spot morning urine samples and their ratios were calculated. Urinary protein measured in 24-hour timed collected urine samples gave the 24-hour UTP excretion rate. In our study, spot morning urine protein creatinine ratio significantly correlated with 24-hour UTP excretion rate in all CRD patients. Severe CRD patients gave significant positive correlation (p<0.05), whereas mild and moderate CRD patients gave very highly significant positive correlation (p<0.001). Therefore, it may be suggested that protein creatinine ratio in spot morning urine can be accepted as a reliable and alternative to 24-hour UTP excretion rate in non-diabetic chronic renal disease patients. This simple and inexpensive procedure will thus simplify the way of establishing the severity of renal disease along with its prognosis.

Comparison of five methods for determination of total plasma protein concentration

Quantitation of exact total protein content is often a key step and is common to many applications in general biochemistry research and routine clinical laboratory practice. Before embarking on any type of protein analysis, particularly comparative techniques, it is important to accurately quantitate the amount of protein in the sample. In order to assess the quality of total protein estimation results, five methods were tested and were applied to the same pooled plasma sample. For this aim, Bradford (Coomassie Brilliant Blue), Lowry (Folin–Ciocalteau), Biüret, Pesce and Strande (Ponceau–S/TCA), and modified method of Schaffner–Weismann (Amido Black 10B) were used. The last two methods employ simultaneous precipitation of proteins with the acid containing dye solutions followed by dissolution of precipitate in a NaOH solution. It is shown that each assay has advantages and disadvantages relative to sensitivity, ease of performance, acceptance in literature, accuracy and reproducibility/coefficient of variation. All of the methods tested show a CV % < 6. Besides pooled plasma, a known concentration of human serum albumin was also analyzed and discussed by means of standardization of plasma total protein content.