Assessment of a biuret method without concentration step for total protein determination in cerebrospinal fluid

1997 ◽  
Vol 30 (4) ◽  
pp. 313-314 ◽  
Author(s):  
Frederic Cotton ◽  
Emile Delobbe ◽  
Beatrice Gulbis
1983 ◽  
Vol 29 (1) ◽  
pp. 126-129 ◽  
Author(s):  
P R Finley ◽  
R J Williams

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.


2020 ◽  
Vol 187 (8) ◽  
pp. e62-e62
Author(s):  
Pablo Jimenez Rihuete ◽  
Nicolas Villarino ◽  
Alicja Pelisiak ◽  
Luis M Rubio-Martinez

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.


1986 ◽  
Vol 32 (2) ◽  
pp. 353-355 ◽  
Author(s):  
L Gerbaut ◽  
M Macart

Abstract Four manual micromethods for protein determination, two turbidimetric (trichloroacetic and sulfosalicylic acid-sodium sulfate) and two colorimetric (Lowry and Coomassie Brilliant Blue--sodium dodecyl sulfate, CBB-SDS) were used to compare the standard curves for total protein (0.30 to 3 g/L) produced with three reference materials: bovine serum albumin, human serum albumin, and diluted human serum. We measured the apparent protein content of a sample of pooled human cerebrospinal fluid by all four methods and with use of all three standards. The only reference material that gave similar results with all four methods was diluted human serum; the CBB-SDS was the only method that gave identical results with all three reference materials. We then measured the protein concentration of 28 individual cerebrospinal fluid samples by the four methods, with diluted human serum as standard. Results by all methods correlated well, but only the sulfosalicylic acid and the CBB-SDS methods gave equivalent results. We conclude that the choice of standard is more important than the method used. However, the CBB-SDS method may be the preferred method because it produced identical standard curves with all three protein standards.


2018 ◽  
Vol 23 (1) ◽  
pp. 70-72
Author(s):  
Diego Franciotta ◽  
Matteo Gastaldi ◽  
Elisabetta Zardini ◽  
Eduardo Nobile-Orazio

2021 ◽  
Vol 11 (3) ◽  
pp. 296
Author(s):  
Lars Hendrik Müschen ◽  
Alma Osmanovic ◽  
Camilla Binz ◽  
Konstantin F. Jendretzky ◽  
Gresa Ranxha ◽  
...  

Approval of nusinersen, an intrathecally administered antisense oligonucleotide, for the treatment of 5q-spinal muscular atrophy (SMA) marked the beginning of a new therapeutic era in neurological diseases. Changes in routine cerebrospinal fluid (CSF) parameters under nusinersen have only recently been described in adult SMA patients. We aimed to explore these findings in a real-world setting and to identify clinical and procedure-associated features that might impact CSF parameters. Routinely collected CSF parameters (leukocyte count, lactate, total protein, CSF/serum albumin quotient (QAlbumin), oligoclonal bands) of 28 adult SMA patients were examined for up to 22 months of nusinersen treatment. Total protein and QAlbumin values significantly increased in the first 10 months, independent of the administration procedure. By month 14, no further increases were detected. Two patients developed transient pleocytosis. In two cases, positive oligoclonal bands were found in the beginning and in four patients throughout the whole observation period. No clinical signs of inflammatory central nervous system disease were apparent. Our data confirm elevated CSF total protein and QAlbumin during nusinersen treatment. These alterations may be caused by both repeated lumbar punctures and the interval between procedures rather than by the medication itself. Generally, there were no severe alterations of CSF routine parameters. These results further underline the safety of nusinersen therapy.


Metabolites ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 268
Author(s):  
Kosuke Saito ◽  
Kotaro Hattori ◽  
Shinsuke Hidese ◽  
Daimei Sasayama ◽  
Tomoko Miyakawa ◽  
...  

Lipidomics provides an overview of lipid profiles in biological systems. Although blood is commonly used for lipid profiling, cerebrospinal fluid (CSF) is more suitable for exploring lipid homeostasis in brain diseases. However, whether an individual’s background affects the CSF lipid profile remains unclear, and the association between CSF and plasma lipid profiles in heathy individuals has not yet been defined. Herein, lipidomics approaches were employed to analyze CSF and plasma samples obtained from 114 healthy Japanese subjects. Results showed that the global lipid profiles differed significantly between CSF and plasma, with only 13 of 114 lipids found to be significantly correlated between the two matrices. Additionally, the CSF total protein content was the primary factor associated with CSF lipids. In the CSF, the levels of major lipids, namely, phosphatidylcholines, sphingomyelins, and cholesterolesters, correlated with CSF total protein levels. These findings indicate that CSF lipidomics can be applied to explore changes in lipid homeostasis in patients with brain diseases.


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