A Micro Biuret Method for Protein Determination Determination of Total Protein in Cerebrospinal Fluid

1953 ◽  
Vol 5 (3) ◽  
pp. 218-222 ◽  
Author(s):  
J. Goa
Keyword(s):  
Cerebrospinal Fluid ◽  
Total Protein ◽  
Protein Determination ◽  
Biuret Method

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.

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.

Multicommutated flow analysis system for determination of total protein in cerebrospinal fluid

Talanta ◽  
2014 ◽  
Vol 128 ◽  
pp. 38-43 ◽  
Author(s):  
Kamil Strzelak ◽  
Agnieszka Wiśniewska ◽  
Dagna Bobilewicz ◽  
Robert Koncki
Keyword(s):  
Cerebrospinal Fluid ◽  
Total Protein ◽  
Flow Analysis ◽  
Analysis System

Assessment of the benzethonium chloride method for routine determination of protein in cerebrospinal fluid and urine.

1983 ◽  
Vol 29 (2) ◽  
pp. 343-345 ◽  
Author(s):  
E Flachaire ◽  
O Damour ◽  
J Bienvenu ◽  
T Aouiti ◽  
R Later
Keyword(s):  
Cerebrospinal Fluid ◽  
Urinary Protein ◽  
Protein Determination ◽  
Benzethonium Chloride ◽  
Chloride Method

Abstract We have tested the characteristics of the method of Iwata and Nishikaze (Clin Chem 25: 1317, 1979). The linearity, sensitivity, and precision are satisfactory and the reactivity of benzethonium chloride with various proteins (albumin, immunoglobulins) is the same. The method has been compared with Meulemans's technique (Clin Chim Acta 5: 757, 1960), routinely used in our laboratories, by analysis of 82 samples of cerebrospinal fluid (CSF) and 119 samples of urine. Our results for cerebrospinal fluid agree well with those of Iwata and Nishikaze (r = 0.976; y = 0.992x - 0.013), but we find their method unsuitable for urinary protein determination, probably because of interfering compounds in urine.

Spinal-Fluid Protein Determination for the Differentiation of Neurologic Disorders

1963 ◽  
Vol 9 (1) ◽  
pp. 97-101 ◽  
Author(s):  
N M Papadopoulos ◽  
W C Hess ◽  
D O'Doherly ◽  
L Wakeman
Keyword(s):  
Total Protein ◽  
Clinical Observation ◽  
Spinal Fluid ◽  
Protein Determination ◽  
Chemical Test ◽  
Neurologic Disorders ◽  
Simple Chemical ◽  
Demyelinating Disorders

Abstract A simple chemical test previously described for the determination of total protein and -globulin was applied to the analysis of spinal fluid specimens (CSF) from non-neurologic and a variety of neurologic disorders. On the basis of the chemical findings, the pathologic specimens analyzed were divided into three groups: (a) nonneurologic and some neurologic conditions with a normal CSF total protein and -globulin concentration; (b) demyelinating disorders with a normal total protein and elevated b.gamma;-globulin concentration; and (c) degenerative and infectious with an elevated total protein and -globulin. A good correlation between chemical findings and clinical observation was obtained.

Methodological features of the spectrophotometric determination of proteins in biological fluids using reactions with brompyrogallol red

2020 ◽  
Vol 86 (2) ◽  
pp. 15-22
Author(s):  
T. B. Pochinok ◽  
P. V. Anisimovich ◽  
Z. A. Temerdashev
Keyword(s):  
Shelf Life ◽  
Spectrophotometric Determination ◽  
Total Protein ◽  
Biological Fluid ◽  
Biological Fluids ◽  
Measurement Techniques ◽  
Protein Determination ◽  
Analytical Properties ◽  
The Impact

Determination of proteins in biological fluids is rather important for diagnostics in current clinical practice. The results of total protein determination depend on the amino-acid composition of the proteins present in the biological fluid. We discuss some aspects of the spectrophotometric determination of proteins in biological fluids, in particular, the methodological features of the technique based on the reaction of proteins with brompyrogallol red (BPGR). The most important advantage of BPGR in the determination of proteins in biological fluids is rather high and equal sensitivity of the dye to the proteins of albumin and globulin fractions, thus minimizing the errors attributed to the mismatch of the protein composition of the analyzed samples and calibration solutions used. The goal of the work is to study the impact of conditions and shelf life of the BPGR solution on the analytical properties of the solution in the spectrophotometric determination of proteins in biological fluids. Stability of the optical and analytical properties of BPGR solutions are studied using Fisher and Student criteria under conditions of different storage temperatures and nature of the stabilizer (ethanol or sodium benzoate) in the reagent solutions. Verification of the correctness of the total protein determination by the proposed method was carried out in spike tests. The introduced additives of standard solutions are prepared from the «Total protein» or «Albumin» calibrators. The developed method of the spectrophotometric determination of the mass concentration of proteins in the urine by the reaction with bromopyrogallol red was tested on real objects, metrologically certified and listed in the Federal register of certified measurement techniques. Analytical and metrological studies have shown that the developed method of protein determination with a reagent based on BPGR provides equal and high sensitivity of determination of albumin and globulin protein fractions in human biological fluids. To increase the shelf life of the reagent solution and preserve the analytical properties of the solution, we recommend to use ethanol as a stabilizer.

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