Effects of dextran on five biuret-based procedures for total protein in serum.

1985 ◽  
Vol 31 (12) ◽  
pp. 2018-2019 ◽  
Author(s):  
D B Barnes ◽  
G F Pierce ◽  
D Lichti ◽  
M Landt ◽  
J Koenig ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Total Protein ◽  
Serum Samples ◽  
Biuret Method ◽  
Automated Instruments ◽  
Roche Cobas

Abstract We evaluated the effect of dextran on values for total protein in serum as measured by the biuret method with five widely used automated instruments: the American Monitor Parallel; the Du Pont aca II; the Roche Cobas-Bio; the Kodak Ektachem 400; and the Beckman Astra 8. Dextran concentrations as great as 25 or 30 g/L had relatively little or no influence on total protein measurements by the latter three instruments. Dextran concentrations exceeding 6 g/L caused falsely low results with the aca, whereas the Parallel gave falsely high results when the dextran concentration exceeded 2 g/L. The aca total protein procedure could be protected from the interference by dextran concentrations up to 30 g/L by injecting 0.4-0.8 mL of ethylene glycol directly into the reagent pack before sampling. However, we could not eliminate the interference with the Parallel procedure by any simple means; we thus recommend that it not be used for measuring total protein in serum samples from patients who are being treated with dextran.

scholarly journals EXERCISE-INDUCED CHANGES IN THE LEVEL OF TOTAL PROTEIN AND ITS FRACTIONS IN THE BLOOD OF HORSES INVOLVED IN RECREATIONAL HORSEBACK RIDING

2020 ◽  
pp. 35-46
Author(s):  
Halyna Tkachenko ◽  
Natalia Kurhaluk ◽  
Irina Tkachova
Keyword(s):  
Total Protein ◽  
Colorimetric Method ◽  
Exercise Session ◽  
Rank Test ◽  
Horseback Riding ◽  
Jugular Veins ◽  
Blood Samples ◽  
Biuret Method ◽  
G Ratio ◽  
Resting Period

The aim of the current study was to do the analysis of the total protein and its fraction in the blood samples of horses, which are involved in recreational horseback riding in the Pomeranian region (Pomeranian Voivodship, northern Poland). Thirteen healthy adult horses from the Pomeranian region in Poland (Strzelinko village, N54°30´48.0´´ E16°57´44.9´´), aged 9.5±2.4 years, including 5 Hucul ponies, 2 Thoroughbred horses, 2 Anglo-Arabian horses, and 4 horses of unknown breed, were used in the current study.Training started at 10:00 AM, lasted 1 hour, and consisted of a ride of cross country by the walking (5 min), the trotting (15 min), the walking (10 min), the trotting (10 min), the walking (5 min), the galloping (5 min), and the walking (10 min). Blood samples were taken from the jugular veins of the animals in the morning time, 90 minutes after feeding, while the horses were in the stables (between 8:30 and 10 AM), and immediately after the exercise session (between 11:00 AM and 2:00 PM). To obtain serum, the blood was collected in plain tubes without anticoagulants. Blood was stored in tubes with K3-EDTA and held on ice until centrifugation at 3,000g for 15 minutes. The plasma was removed.The total protein and its fractions were measured at +23°C by the biuret method with the use of commercially available reagents and a compact semi-automated analyzer RX Monza (Randox Laboratories LTD., UK) according to the procedures described by the manufacturer. The biuret method is the most widely used colorimetric method for the determination of the total protein concentration in serum because of its simplicity, precision, and accuracy. The absorbance of each sample was measured in duplicate.Results are expressed as mean ± S.E.M. All variables were tested for normal distribution using the Kholmogorov-Smirnov test (p>0.05). To find significant differences (significance level, p<0.05) between at the rest and after exercise, the Wilconson signed-rank test was applied to the data. All statistical analyses were performed using STATISTICA 8.0 software (StatSoft, Krakow, Poland). The total protein level in the blood of horses exhibited a non-significant increase (by 7.1%, p>0.05) immediately after exercise as compared to the resting period. Also, the albumin and globulin levels in the blood of horses were non-significantly increased by 5.9% (р>0.05) and 8.1% (р>0.05) after the training sessions. There were no significant differences in serum albumin/globulin ratio between the resting period and after exercise (0.997±0.09 vs. 0.977±0.08). The results of our current study showed that exercise has a statistically non-significant effect on the total proteins and their fractions in equine serum. The fractions and the A/G ratio were within the range of values obtained in horses in other studies. Thus, it was found that total protein and its fractions were increased in horses after training, and this increase was insignificant. This increase has a direct correlation with exercise. In this paper, it is shown that training can change the physiology and affect the biochemistry of hematobiochemical blood parameters in horses subjected to physical exertion.

Verification of Harmonization of Serum Total and Free Prostate-Specific Antigen (PSA) Measurements and Implications for Medical Decisions

2020 ◽  
Author(s):  
Simona Ferraro ◽  
Marco Bussetti ◽  
Sara Rizzardi ◽  
Federica Braga ◽  
Mauro Panteghini
Keyword(s):  
Prostate Specific Antigen ◽  
Information Needs ◽  
Specific Antigen ◽  
International Standards ◽  
Serum Samples ◽  
Medical Decisions ◽  
Measuring Systems ◽  
Performance Specifications ◽  
Current Measuring ◽  
Roche Cobas

Abstract Background Previous studies have shown that the harmonization of prostate-specific antigen (PSA) assays remained limited even after the introduction of WHO International Standards. This information needs updating for current measuring systems (MS) and reevaluation according to established analytical performance specifications (APS) and the characteristics of antibodies used. Methods Total (tPSA) and free (fPSA) PSA were measured in 135 and 137 native serum samples, respectively, by Abbott Alinity i, Beckman Access Dxl, Roche Cobas e801, and Siemens Atellica IM MSs. Passing–Bablok regression and difference plots were used to compare results from each MS to the all-method median values. Agreement among methods was evaluated against APS for bias derived from biological variation of the 2 measurands. Results The median interassay CV for tPSA MSs (11.5%; 25–75th percentiles, 9.2–13.4) fulfilled the minimum APS goal for intermethod bias (15.9%), while the interassay CV for fPSA did not [20.4% (25–75th percentiles, 18.4–22.7) vs goal 17.6%]. Considering the all-method median value of each sample as reference, all tPSA MSs exhibited a mean percentage bias within the minimum goal. On the other hand, Alinity (+21.3%) and Access (−24.2%) were out of the minimum bias goal for fPSA, the disagreement explained only in minimal part by the heterogeneity of employed antibodies. Conclusions The harmonization among tPSA MSs is acceptable only when minimum APS are applied and necessitates further improvement. The marked disagreement among fPSA MSs questions the use of fPSA as a second-level test for biopsy referral.

Assay of cerebrospinal fluid protein: a rate biuret method evaluated.

1983 ◽  
Vol 29 (1) ◽  
pp. 126-129 ◽  
Author(s):  
P R Finley ◽  
R J Williams
Keyword(s):  
Cerebrospinal Fluid ◽  
Total Protein ◽  
Protein Concentration ◽  
Protein A ◽  
Colorimetric Method ◽  
Total Protein Concentration ◽  
Reaction Cell ◽  
Biuret Method ◽  
Automated Instrument ◽  
Cerebrospinal Fluid Protein

Abstract We evaluated a rate colorimetric method (Beckman) for measuring total protein in cerebrospinal fluid. The automated instrument we used was Beckman's ASTRA TM. A 100-microL sample of spinal fluid is introduced into the biuret reagent in the reaction cell and the increase in absorbance at 545 nm is monitored for 20.5 s. Solid-state circuits determine the rate of alkaline biuret-protein chelate formation, which is directly proportional to the total protein concentration in the sample. The linear range of measurement is 120 to 7500 mg/L. Day-to-day precision (CV) over the range of 150 to 1200 mg/L ranged from 15.2 to 2.3%. The method was unaffected by radical alteration of the albumin/globulin ratio, but there is a positive interference in the presence of hemoglobin, a suppression in the presence of bilirubin, and no effect by xanthochromia. The method is precise, accurate, rapid, and convenient. The method was compared with the trichloroacetic acid method as performed on the Du Pont aca III, giving a correlation coefficient (r2) of 0.9693. The method is precise, accurate, rapid, and convenient.

Concentration of dipotassium ethylenediaminetetraacetic acid but not lithium heparin affects total protein determination in equine synovial fluid

2020 ◽  
Vol 187 (8) ◽  
pp. e62-e62
Author(s):  
Pablo Jimenez Rihuete ◽  
Nicolas Villarino ◽  
Alicja Pelisiak ◽  
Luis M Rubio-Martinez
Keyword(s):  
Synovial Fluid ◽  
Cross Section ◽  
Total Protein ◽  
Gold Standard ◽  
Ethylenediaminetetraacetic Acid ◽  
Protein Determination ◽  
Collection Tube ◽  
Refractometric Determination ◽  
Biuret Method

BackgroundRefractometric determination of total protein (TP) in synovial fluid (SF) is commonly used for diagnosis and monitoring of synovial sepsis in horses. Previous studies have shown that elevated concentrations of certain anticoagulants may overestimate refractometric determination of TP concentration.ObjectivesThe aim of the study was to evaluate the effect of different concentrations of dipotassium EDTA (K2EDTA) and lithium heparin (LH) on TP determination by using a hand-held refractometer in equine synovial fluid.Study designCross-section observational study.MethodsThirty samples of synovial fluid obtained from 22 horses with different synovial conditions were collected. Synovial fluid samples were separated into different aliquots and placed in commercially available collection tubes containing K2EDTA or LH at four different concentrations (1.76, 3.52, 7.04 and 17.6 mg/ml for K2EDTA; 16, 32, 64 and 160 IU/ml for LH) . Refractometric TP determination was performed on untreated and K2EDTA and LH aliquots with a hand-held refractometer and by spectophotometric Biuret method as the gold standard.ResultsRefractometric TP determination was overestimated in SF samples containing 10 times the recommended K2EDTA concentrations. Lower concentrations of K2EDTA and LH concentrations did not affect refractometric TP determinations.Main limitationsLimited number of samples mostly obtained from large synovial structures.ConclusionTo avoid incorrect TP determination, the use of LH containing collection tubes may be an appropriate alternative when the SF volume available is not enough to fill the K2EDTA collection tube.

scholarly journals Discrepancies in Electrolyte Measurements by Direct and Indirect Ion Selective Electrodes due to Interferences by Proteins and Lipids

2020 ◽  
Vol 12 (02) ◽  
pp. 084-091
Author(s):  
Parul Chopra ◽  
Sudip Kumar Datta
Keyword(s):  
Confidence Interval ◽  
Regression Model ◽  
Analysis Of Variance ◽  
Total Protein ◽  
Multivariate Regression ◽  
Ion Selective Electrodes ◽  
Serum Samples ◽  
Serum Total Protein ◽  
Clinically Significant ◽  
Patient Subgroups

Abstract Objectives We aim to report the simultaneous effect of different protein and lipid concentrations on sodium (Na+) and potassium (K+) measurement by direct and indirect ion selective electrodes (dISE and iISE) in patient samples. Materials and Methods Na+ and K+ were measured in 195 serum samples received in the laboratory using iISE by Roche Modular P800 autoanalyzer and using dISE by XI-921 ver. 6.0 Caretium electrolyte analyzer. Serum total protein (TP), cholesterol (Chol), and triglycerides (TG) were measured using conventional photometric methods on Roche Modular P800 autoanalyzer. Differences for each pair of results for Na+ (Diff_Na+ = [Na+ dISE–Na+ iISE]) and K+ (Diff_K+ = [K+ dISE–K+ iISE]) were calculated. Patient subgroups with high, normal, or low TP (< 5, 5–7.9, or ≥ 8 g/dL), Chol (< 150, 150–299, or ≥300 mg/dL), or TG (< 150, 150–299, or ≥300 mg/dL) were compared using analysis of variance. Note that 95% confidence interval of Diff_Na+ and Diff_K+ were calculated to see the number of samples showing clinically significant differences. Results Diff_Na+ (p = 0.007) and Diff_K+ (p = 0.002) were found significant between samples with normal and high TP. However, effect of TG was not significant. Chol concentration affected Diff_Na+ significantly between low versus normal (p = 0.002), and high versus normal (p = 0.031) Chol groups. Diff_K+ was significant (p = 0.009) between low versus normal Chol. Clinically relevant disagreement of ≥|5| mmol/L for Na+ was observed in high percentage of samples including all subcategories; however, for K+ only 3.6% of the total samples showed disagreement of ≥ |0.5| mmol/L. A multivariate regression equation based on fit regression model was also derived. Conclusion Summarily, interchangeable use of electrolyte results from dISE and iISE is not advisable, especially in a setting of hyperproteinemia (≥8 g/dL) or hypercholesterolemia (≥300 mg/dL); more so for Na+.

Upper reference limits for cerebrospinal fluid total protein and albumin quotient based on a large cohort of control patients: implications for increased clinical specificity

2016 ◽  
Vol 54 (2) ◽  
Author(s):  
Harald Hegen ◽  
Michael Auer ◽  
Achim Zeileis ◽  
Florian Deisenhammer
Keyword(s):  
Cerebrospinal Fluid ◽  
Total Protein ◽  
Neurological Disease ◽  
Large Cohort ◽  
Barrier Dysfunction ◽  
Serum Samples ◽  
Age Related ◽  
Reference Limits ◽  
Future Revision ◽  
Work Up

AbstractDetermination of cerebrospinal fluid (CSF) total protein (TP) as well as of CSF/serum albumin quotient (Qalb) is part of the routine CSF work-up. However, currently used upper reference limits (URL) are not well validated leading to over-reporting of blood-CSF barrier dysfunction in approximately 15% of patients without neurological disease. The objective of this study was to determine age-related URL for CSF TP and Qalb in a cohort of control patients.A total of 332 paired CSF and serum samples of patients without objective clinical and paraclinical findings of a neurological disease were analyzed for CSF TP and Qalb. CSF TP was measured by spectrophotometry and albumin in CSF and serum by nephelometry.CSF TP concentration and Qalb significantly correlated with age. In subjects at the age of 18–70 years, median CSF TP ranged from 320 to 460 mg/L and URL defined as the 95th percentile were 530–690 mg/L. Median Qalb ranged from 4.1 to 6.1 and URL from 8.7 up to 11.0. For URL of Qalb we calculated the following formula: age/25+8.Age-dependent URL for CSF TP and Qalb are presented here in a large cohort of control patients. They are higher than those currently recommended and this probably explains why isolated blood-CSF barrier dysfunction has been apparently over-reported. These new URL might be considered in a future revision of CSF guidelines.

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