DIRECT MEASUREMENT OF ARGININE-VASOPRESSIN IN HUMAN SERUM WITHOUT EXTRACTION PROCEDURE

1975 ◽  
Vol 80 (1_Suppla) ◽  
pp. S130 ◽  
Author(s):  
H. Wagner ◽  
V. Maier ◽  
H.-J. Herrmann ◽  
H. E. Franz
Keyword(s):  
Human Serum ◽  
Direct Measurement ◽  
Arginine Vasopressin ◽  
Extraction Procedure

RADIOIMMUNOASSAYS OF 3,5,3′-TRIIODO-L-THYRONINE WITH AND WITHOUT A PRIOR EXTRACTION STEP

1975 ◽  
Vol 80 (1) ◽  
pp. 58-69 ◽  
Author(s):  
A. Burger ◽  
C. Sakoloff ◽  
V. Staeheli ◽  
M. B. Vallotton ◽  
S. H. Ingbar
Keyword(s):  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Normal Values ◽  
Covalent Binding ◽  
Extraction Procedure ◽  
Mixed Population ◽  
Coupling Agents ◽  
Extraction Step ◽  
The Mean

ABSTRACT Two radioimmunoassays for triiodothyronine (T3) are described, one of which includes an extraction step, while the other does not. To raise antibodies, two carrier proteins and different coupling agents were used, namely haemocyanin and diazotized benzidine or human serum albumin and carbodiimide. In the case of T3 coupled to haemocyanin by diazotized benzidine, evidence of covalent binding of the hapten to the protein was obtained. In the case of T3 coupled to human serum albumin, little evidence of covalent linkage was available. Nevertheless immunization was successful in both cases. The radioimmunoassay in unextracted serum was highly reproducible and precise (intra-assay variability 5.2% inter-assay variability 8.1%). Normal values were determined which clearly indicate a fall in the serum T3 concentration with increasing age. In men the fall occurs in the fifth decade. In women the T3 starts to fall only after 70 years of age. In 31 cases of hyperthyroidism the serum T3 concentration ranged from 2.26 to 10.4 ng T3/ml. In 10 cases of hypothyroidism the values ranged from 0 to 0.8 ng T3/ml. The radioimmunoassay using an extraction procedure was less extensively used since it was found to be less reproducible (intra-assay variability 7.5%, inter-assay 12.25%). The normal values were determined with a mixed population aged 20–50. The mean ± 2 sd was 0.9 ± 0.36 ng T3/ml (n=52). In 17 cases of hypothyroidism the values ranged from 0 to 0.6 ng T3/ml and in 22 cases of hyperthyroidism from 2 to 14.4 ng T3/ml.

A Radioreceptor Assay for Insulin: Direct Measurement of Human Serum Insulin

1982 ◽  
Vol 14 (07) ◽  
pp. 339-342 ◽  
Author(s):  
K. Nakao ◽  
A. Takeda ◽  
S. Kagawa ◽  
S. Shimizu ◽  
A. Matsuoka
Keyword(s):  
Human Serum ◽  
Direct Measurement ◽  
Serum Insulin ◽  
Radioreceptor Assay

Analysis of UK Sera for Aflatoxin by Enzyme-linked Immunosorbent Assay

1988 ◽  
Vol 7 (4) ◽  
pp. 353-356 ◽  
Author(s):  
A.P. Wilkinson ◽  
D.W. Denning ◽  
M.R.A. Morgan
Keyword(s):  
Human Serum ◽  
Direct Measurement ◽  
Immunosorbent Assay ◽  
Human Exposure ◽  
Blood Donors ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fungal Metabolites ◽  
Serum Samples ◽  
Imported Food ◽  
The Uk

1 Aflatoxins are toxic, carcinogenic secondary fungal metabolites produced by certain moulds that commonly infest foods. Measurement of aflatoxins in human serum would give a direct measurement of exposure. 2 Twenty-seven serum samples from UK blood donors were found to contain aflatoxin levels not greater than 64 pmol/1 (20 pg/ml) by an enzyme-linked immunosorbent assay. 3 These findings may indicate that present UK guideline tolerances for aflatoxin in imported food are effective in limiting human exposure to toxic aflatoxins in the UK diet, though further work would be needed to confirm this. In particular, sub-populations suspected of being at higher risk may need special considerations.

scholarly journals A novel method for direct measurement of complement convertases activity in human serum

2014 ◽  
Vol 178 (1) ◽  
pp. 142-153 ◽  
Author(s):  
A. M. Blom ◽  
E. B. Volokhina ◽  
V. Fransson ◽  
P. Strömberg ◽  
L. Berghard ◽  
...  
Keyword(s):  
Human Serum ◽  
Direct Measurement ◽  
Novel Method

Novel Method Development for Extraction and Analysis of Pesticide Residues in Human Serum Samples

2021 ◽  
Vol 18 (4) ◽  
pp. 79-86
Author(s):  
Divya Kottadiyil ◽  
Shital Deore ◽  
P. Sivaperumal
Keyword(s):  
Human Serum ◽  
Pesticide Residue ◽  
Pesticide Residues ◽  
Method Development ◽  
Residue Analysis ◽  
Extraction Procedure ◽  
Pesticide Residue Analysis ◽  
Serum Samples ◽  
Human Serum Samples ◽  
Vital Functions

In recent years, exposure to pesticides has gained widespread attention due to their adverse health effects. Long-term exposure to pesticides has shown hazardous effects on vital functions of the human nervous and reproductive systems. Therefore, it is crucial to determine the extent of pesticide exposure in humans. Primarily, it is quite challenging to determine trace levels of pesticide residues in biological matrices. Hence, a quick, multi-residue extraction procedure was experimented for pesticide residue analysis in human serum. Herein, the original QuEChERS extraction method was modified for achieving the best possible recoveries. A total of 15 representative pesticides from each class were selected and fortified into the human serum samples. The extraction was performed by employing acidified solution containing acetonitrile and ethyl acetate followed by vortex and centrifugation. The obtained aqueous layer was collected and vapourised to dryness and d-SPE clean-up was conducted utilising PSA. The extracted sample was injected into the GC-MS/MS system under MRM mode. The method development parameters such as linearity, % RSD, accuracy, LOD, LOQ and % ME were assessed. The results obtained for the serum matrix were found to be within the criteria mentioned in European Union SANTE/12682/2019 guidelines for method validation. The developed solitary method is quick, simple and highly efficient for routine pesticide residue analysis. Hence, a wide spectrum of pesticides can be analysed utilising the proposed method for human serum.

Some problems associated with assay of 25-hydroxycalciferol in human serum.

1977 ◽  
Vol 23 (5) ◽  
pp. 806-810 ◽  
Author(s):  
R S Mason ◽  
S Posen
Keyword(s):  
Human Serum ◽  
Silicic Acid ◽  
Rat Kidney ◽  
Extraction Procedure ◽  
Normal Subjects ◽  
Good Alternative ◽  
Alternative Methods ◽  
Control Serum ◽  
Free Material ◽  
Rat Kidney Cytosol

Abstract Methods available for the assay of 25-hydroxycalciferol in human serum are evaluated and compared to one another. Ethanol was chosen for use in the initial extraction procedure and rat-kidney cytosol as the binding protein, although good alternative methods are also available. We used silicic acid for chromatography and found this an essential step. Reproducibility was increased when, after "bound" and "free" material were separated, an aliquot of the supernate was pipetted into the counting vial instead of the entire supernatant fluid being decanted. Beta-lipo-protein added to the assay system was of no advantage; added bovine serum albumin interfered with the assay by giving rise to high blank values. With ethanol extraction, silicic acid chromatography, rat kidney cytosol and separation on dextran-coated charcoal, sera from normal subjects showed a mean 25-hydroxycalciferol concentration of 28.5 microng/liter (range, 13.1 to 43.9) during the fall season. Coefficients of variation for a control serum were 4.9% (intra-assay) and 10.9% (interassay).

Quantitative gas-chromatographic flame-ionization method for p-chlorophenoxyisobutyric acid in human serum and saliva.

1976 ◽  
Vol 22 (6) ◽  
pp. 884-888 ◽  
Author(s):  
J N Connor ◽  
G F Johnson ◽  
H M Solomon
Keyword(s):  
Human Serum ◽  
Extraction Procedure ◽  
Average Dose ◽  
Unbound Fraction ◽  
Butyl Esters ◽  
Flame Ionization ◽  
Double Extraction ◽  
High Concentrations ◽  
Gas Chromatographic Method ◽  
Chlorophenoxyisobutyric Acid

Abstract We describe a gas-chromatographic method for p-chlorophenoxyisobutyric acid (I) the active metabolite of clofibrate. The drug and internal standards are separated from either serum or saliva by a double extraction procedure and converted to the corresponding butyl esters by reaction with iodobutane in a mixture of methanol and N,N-di-methylacetamide containing tetramethylammonium hydroxide. Within-run CV of this assay at a serum I concentration of 79.2 mg/liter was 2.3% and at a salivary I concentration of 2.5 mg/liter was 2.1%. Precision during four months of the serum and salivary assays at these concentrations was 4.1% and 6.2%, respectively. The mean serum concentration of I (12 h after dose) in patients receiving the drug at an average dose of 28.0 mg/kg per day was 109.6 mg/liter. Serum and salivary concentrations of I as determined by our procedure were used to calculate the unbound fraction of drug in human serum. Such measurements can be used to monitor therapy in patients with renal disease, where drug toxicity may arise from high concentrations of unbound I.

Direct measurement of antigens in serum by time-resolved fluoroimmunoassay.

1985 ◽  
Vol 31 (1) ◽  
pp. 50-53 ◽  
Author(s):  
J E Kuo ◽  
K H Milby ◽  
W D Hinsberg ◽  
P R Poole ◽  
V L McGuffin ◽  
...  
Keyword(s):  
Human Serum ◽  
Direct Measurement ◽  
Immunoglobulin G ◽  
Chelating Agent ◽  
Competitive Binding ◽  
Fluorescence Immunoassay ◽  
Time Resolved ◽  
Rapid Procedure ◽  
Bifunctional Chelating Agent ◽  
Fluorescence Label

Abstract A long-lived fluorescence label (Tb3+) has been attached to the antigen of interest by using a bifunctional chelating agent 1-(p-benzenediazonium)-EDTA. A nonequilibrium competitive-binding immunoassay protocol, in conjunction with time-resolved detection of the long-lived fluorescence label, allows the antigen to be analyzed directly in samples containing diluted human serum. Results obtained for immunoglobulin G with this simple and rapid procedure correlated well (r = 0.93) with those by a commercially available fluorescence immunoassay method.

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