scholarly journals Validation of a radioimmunoassay of serum trypsin-like immunoreactivity in ferrets

2018 ◽  
Vol 30 (4) ◽  
pp. 517-522
Author(s):  
Cory S. Bridges ◽  
Pamela S. Miller ◽  
Jonathan A. Lidbury ◽  
Jan S. Suchodolski ◽  
Yaling Yi ◽  
...  
Keyword(s):  
Reference Interval ◽  
Exocrine Pancreatic Function ◽  
Pulmonary Diseases ◽  
Analytical Sensitivity ◽  
Mustela Putorius ◽  
Serum Samples ◽  
Coefficients Of Variation ◽  
Upper Limits ◽  
Serum Trypsin

Measurement of serum trypsin-like immunoreactivity (TLI) is used to assess exocrine pancreatic function in dogs and cats. Ferrets ( Mustela putorius furo) serve as valuable animal models for human diseases such as cystic fibrosis and other pulmonary diseases, and may be a useful model of other diseases including pancreatitis. We developed and analytically validated a competitive radioimmunoassay (RIA) for measurement of TLI in ferret serum by determination of analytical sensitivity, assay linearity, accuracy of spiking recovery, precision, and reproducibility. Analytical sensitivity of the assay was 0.55 μg/L. Observed-to-expected (O/E) ratio for dilutional parallelism was 90.2–127.9% (mean: 108.1 ± 11.9%). The O/E ratio for spiking recovery was 94.5–113.0% (mean: 103.9 ± 7.2%). The intra- and inter-assay coefficients of variation (CVs) were 2.7–5.7% and 3.5–8.2%, respectively. The reference interval (RI) for serum TLI derived from 31 healthy ferrets was 28–115 μg/L; the 90% confidence interval for the lower and upper limits of the RI were 10.0–32.1 μg/L and 103–126 μg/L, respectively. This TLI RIA is analytically sensitive, sufficiently linear, accurate, precise, and reproducible for the measurement of TLI in ferret serum samples.

scholarly journals Diagnostic performance of a new highly sensitive thyroglobulin immunoassay

2004 ◽  
Vol 182 (2) ◽  
pp. 287-294 ◽  
Author(s):  
A Iervasi ◽  
G Iervasi ◽  
A Bottoni ◽  
G Boni ◽  
C Annicchiarico ◽  
...  
Keyword(s):  
Clinical Performance ◽  
Thyroid Tissue ◽  
Cancer Recurrence ◽  
Analytical Sensitivity ◽  
Serum Thyroglobulin ◽  
Coefficients Of Variation ◽  
Highly Sensitive ◽  
Chemiluminescent Immunoassay ◽  
Free Serum

The determination of serum thyroglobulin (Tg) is commonly used for detecting the presence of residual thyroid tissue or cancer recurrence in patients treated for differentiated thyroid cancer (DTC). The aim of the study was to evaluate the performance characteristics of a recently introduced fully automated chemiluminescent immunoassay, based on four monoclonal antibodies and which produces results in 40 min. Analytical sensitivity (0.01 micro g/l) was computed from 20 replicates of the zero calibrator and of the 'Tg-free' sample pool. Functional sensitivity (0.1 micro g/l at 20 coefficients of variation percent) was determined from the imprecision profile obtained by assaying ten serum pools. The reliability of the measurements in the low concentration range (Tg<1 micro g/l) has been checked by progressive dilution with the 'Tg-free' serum of a sample pool at 5.27 micro g/l; measured values were very close to the expected values (recovery 100-133%).Cut-off at the 99th percentile in DTC stage I 'disease-free' treated patients (n=53) was 0.16 micro g/l. Tg measurement in basal conditions during L-thyroxine suppression therapy and 5 days after recombinant human TSH stimulation was performed in 22 patients with DTC. In 80% of patients with basal Tg<0.1 micro g/l (12/15), Tg remained<0.1 micro g/l after stimulation, and in all of these Tg was<1 micro g/l.Our results have indicated the optimal analytical and clinical performance of this Tg immunoassay and encourage further studies on larger populations of patients with DTC.

Differential assay of zidovudine and its glucuronide metabolite in serum and urine with a radioimmunoassay kit

1990 ◽  
Vol 36 (6) ◽  
pp. 897-900 ◽  
Author(s):  
S M Tadepalli ◽  
L Puckett ◽  
S Jeal ◽  
L Kanics ◽  
R P Quinn
Keyword(s):  
Inhibitory Concentration ◽  
Serum Samples ◽  
Lower Detection Limit ◽  
Coefficients Of Variation ◽  
Lower Detection ◽  
Before And After ◽  
The Difference ◽  
Glucuronide Metabolite ◽  
Serum And Urine

Abstract We developed an ancillary procedure for the ZDV-Trac RIA (Incstar) to allow simultaneous determination of both zidovudine (3'-azido-3'-deoxythymidine, ZDV, AZT, Retrovir) and its metabolite, the glucuronide of ZDV (3'-azido-3'-deoxy-5'-O-beta-D-glucopyranuronosylthymidine, ZDVG, GAZT), in human serum and urine. Using the ZDV-Trac RIA, we measured ZDV concentrations before and after ZDVG in samples was hydrolyzed to ZDV by beta-glucuronidase (EC 3.2.1.31); ZDVG concentration was calculated as the difference between the two results. This method enables rapid evaluation of a large number of samples with a total turn-around time of 6 h. The lower detection limit of the RIA was 0.27 micrograms/L; the measurements varied linearly with ZDV concentrations from 0.27 to 217 micrograms/L, with the 50% inhibitory concentration being approximately 10 micrograms/L. Analytical recoveries of inhouse serum and urine controls for both ZDV and ZDVG exceeded 90%. Coefficients of variation (CVs) of serum controls were less than 6% for ZDV and less than 11% for ZDVG; for urine controls, CVs for both ZDV and ZDVG were less than 6%. Results for ZDVG concentrations obtained by HPLC and by the ZDV-Trac RIA system compared well: r = 0.978, slope 1.0, for serum samples, and r = 0.993, slope 1.09, for urine samples.

scholarly journals Direct Determination of Lipoprotein Particle Sizes and Concentrations by Ion Mobility Analysis

2008 ◽  
Vol 54 (8) ◽  
pp. 1307-1316 ◽  
Author(s):  
Michael P Caulfield ◽  
Shuguang Li ◽  
Gloria Lee ◽  
Patricia J Blanche ◽  
Wael A Salameh ◽  
...  
Keyword(s):  
Ion Mobility ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Direct Determination ◽  
Serum Samples ◽  
Lipoprotein Particles ◽  
Lipoprotein Subclasses ◽  
Scan Time ◽  
Coefficients Of Variation

Abstract Background: Current methods for measuring the concentrations of lipoprotein particles and their distributions in particle subpopulations are not standardized. We describe here and validate a new gas-phase differential electrophoretic macromolecular mobility-based method (ion mobility, or IM) for direct quantification of lipoprotein particles, from small, dense HDL to large, buoyant, very-low-density lipoprotein (VLDL). Methods: After an ultracentrifugation step to remove albumin, we determined the size and concentrations of lipoprotein particles in serum samples using IM. Scan time is 2 min and covers a particle range of 17.2–540.0 Å. After scanning, data are pooled by totaling the particle number across a predetermined size range that corresponds to particular lipoprotein subclasses. IM results were correlated with those of standard methods for cholesterol and apolipoprotein analysis. Results: Intra- and interassay coefficients of variation for LDL particle size were &lt;1.0%. The intra- and interassay variation for LDL and HDL particle subfraction measurements was &lt;20%. IM-measured non-HDL correlated well with apolipoprotein B (r = 0.92). Conclusions: The IM method provides accurate, reproducible, direct determination of size and concentration for a broad range of lipoprotein particles. Use of this methodology in studies of patients with cardiovascular disease and other pathologic states will permit testing of its clinical utility for risk assessment and management of these conditions.

Mechanized determination of the apparent unbound unconjugated bilirubin concentration in serum.

1979 ◽  
Vol 25 (8) ◽  
pp. 1444-1447 ◽  
Author(s):  
R P Wennberg ◽  
L F Rasmussen ◽  
C E Ahlfors ◽  
T Valaes
Keyword(s):  
Total Bilirubin ◽  
Gel Filtration ◽  
Operation Time ◽  
Serum Samples ◽  
Bilirubin Concentration ◽  
Coefficients Of Variation ◽  
Control Serum ◽  
Total Bilirubin Concentration ◽  
Unbound Bilirubin

Abstract The peroxidase method for determining the apparent unbound bilirubin concentration in serum has been automated by use of a programmable, computer-directed spectrophotometer. This mechanized assay determines the total bilirubin concentration and apparent unbound bilirubin concentration in serum samples and titrates the serum with bilirubin to estimate the effect of increasing total bilirubin concentrations on the apparent unbound bilirubin concentration. The entire analysis requires 0.1 mL of serum and 4 min operation time, as compared with about 30 min for the manual method. The coefficients of variation for determination of the apparent unbound bilirubin concentration in bilirubin-enriched commercial control serum were 2.8% within-day and 5.6% between-day. Bilirubin--albumin binding in serum samples from infants with severe hyperbilirubinemia was analyzed by the manual peroxidase method, the automated peroxidase method, and Sephadex gel filtration. Good correlation was found among all three methods.

scholarly journals Determination of Retinol-Binding Protein in Serum by Kinetic Immunonephelometry with Polyethylene Glycol Pretreatment

1984 ◽  
Vol 21 (6) ◽  
pp. 484-487 ◽  
Author(s):  
M J Hallworth ◽  
Jacqueline Calvin ◽  
C P Price
Keyword(s):  
Polyethylene Glycol ◽  
Detection Limit ◽  
Binding Protein ◽  
Regression Line ◽  
Retinol Binding Protein ◽  
Serum Samples ◽  
Coefficients Of Variation ◽  
Method Yield ◽  
Scattering Material

This work describes the use of polyethylene glycol as a pretreatment reagent to remove endogenous light scattering material from serum samples prior to automated immunonephelometric analysis on a centrifugal analyser. An assay system for retinol-binding protein is described, which allows rapid (10 minutes) quantitation of retinol-binding protein in serum samples with a detection limit of 5 mg/L and between-assay coefficients of variation ranging from 2·9% to 4·0%. The assay range is 5–80 mg/L and accuracy comparisons with a Mancini single radial immunodiffusion method yield a regression line y=0·89x+0·52 ( r=0·98, n=22). The problem of analyte precipitation associated with use of pretreatment regimes is discussed.

scholarly journals Development of immunoradiometric assay for quantitative determination of free prostate-specific antigen

2005 ◽  
Vol 24 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Miroslava Jankovic ◽  
Maja Kosanovic ◽  
Ljiljana Hajdukovic-Dragojlovic ◽  
Snezana Golubovic
Keyword(s):  
Quantitative Determination ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Laboratory Diagnostics ◽  
Immunoradiometric Assay ◽  
Serum Samples ◽  
Coefficients Of Variation ◽  
One Step ◽  
Prostate Diseases

In this study we reported the development and analytical validation of new assay for quantitative determination of free prostate-specific antigen, fPSA. It is formulated as one step, two-site "sandwich" immunoradiometric assay. Specificity of this assay was achieved by using epitope-1-reactive anti-fPSA antibody as tracer antibody. Assay was calibrated against first international standard 96/668, and its detection limit was determined as 0.08 mg/L. Intra- and inter-assay coefficients of variation were 3.42-7.53% and 7.04-8.33%, respectively. Measured concentrations of serially diluted serum samples were close to the calculated concentrations, indicating good linearity with recovery percentage ranging from 98.7-107.4%. Analytical performance characteristics of fPSA assay speaks in favor of its use as a reliable tool in laboratory diagnostics relating to prostate diseases.

Clinical usefulness of an enzymatic determination of total urinary polyamines, excluding cadaverine.

1988 ◽  
Vol 34 (11) ◽  
pp. 2271-2274 ◽  
Author(s):  
F Mashige ◽  
N Tanaka ◽  
T Murakami ◽  
H Shimosaka ◽  
S Kamei ◽  
...  
Keyword(s):  
Reference Interval ◽  
The Body ◽  
Enzymatic Method ◽  
Pathological Changes ◽  
Enzymatic Determination ◽  
Coefficients Of Variation ◽  
Physiological Variations ◽  
Urinary Polyamines ◽  
Total Concentrations

Abstract In one widely used enzymatic method for urinary polyamines, the total concentrations of four polyamines--putrescine, spermidine, spermine, and cadaverine--are determined. We report here a simple enzymatic method for measuring the total concentrations of urinary polyamines except cadaverine. The coefficients of variation (CV) for within-run measurements by this method were 4.3% (means = 17.2 mumol/L) and 1.5% (means = 66.5 mumol/L), between-run CVs were 4.8% (means = 16.8 mumol/L) and 1.8% (means = 67.5 mumol/L). The central 95% normal reference interval was 12.3-29.1 mumol/g creatinine for men and 14.1-36.8 mumol/g creatinine for women. In some cases, physiological variations in urinary polyamine excretion were large, mainly because of variations in cadaverine excretion, even in health. Pathological changes in polyamine production in the body may therefore be more easily shown by the excretion of total polyamines excluding cadaverine than by that including cadaverine.

Fluorometric Microassays for the Determination of Cathepsin L and Cathepsin S Activities in Tissue Extracts

1999 ◽  
Vol 380 (9) ◽  
pp. 1109-1116 ◽  
Author(s):  
Bernd Werle ◽  
Alexander Staib ◽  
Britta Jülke ◽  
Werner Ebert ◽  
Pavel Zladoidsky ◽  
...  
Keyword(s):  
Cathepsin B ◽  
Large Scale ◽  
Cathepsin L ◽  
Microtiter Plate ◽  
Cathepsin S ◽  
Analytical Sensitivity ◽  
Microtiter Plate Assay ◽  
Plate Assay ◽  
Coefficients Of Variation

Abstract We established a continuous semi-microassay, and for large-scale studies both a stopped and a continuous microtiter plate assay for the fluorometric determination of cathepsin L and cathepsin S activities in body fluids, tissues or cell extracts in the presence of cathepsin B. For the detection of enzymatic activities we used the synthetic substrate Z-Phe-Arg-AMC, and for discrimination between cathepsin L, S and cathepsin B the specific inhibitor CA-074 for blocking interfering cathepsin B activities was applied. Furthermore, we took advantage of the stability of cathepsin S at pH 7.5 for further differentiation between cathepsin L and cathepsin S activities. The kinetic assays were characterized in terms of imprecision, analytical sensitivity, accuracy and substrate concentration. The within-run coefficients of variation were found to be 4.9%–7.2% for the continuous semi-microassay, 10.3%–11.7% for the stopped, and 4.5%–11.8% for the continuous microtiter plate assay. The between-days coefficients of variation for the continuous semimicroassay were 8.1%–8.9%, while for the stopped and continuous microtiter plate assays the coefficients were 11.2%–13.5% and 5.8%–12.2%, respectively. Compared to the continuous semi-microassay, the stopped and the continuous microtiter plate assays showed 3-fold and 11-fold higher sensitivity, respectively. Comparison between the continuous enzyme activity assays at substrate concentrations of 40 μM and 200μM demonstrated a significant correlation of r = 0.97 and r = 0.99, respectively. The newly developed microtiter plate assay will allow efficient, sensitive and high precision determination of cathepsin L and cathepsin S activities in large-scale studies of cysteine-cathepsin dependent diseases.

Determination of a Beckman Coulter AU turbidometric method-specific caeruloplasmin reference interval

2021 ◽  
pp. 000456322198936
Author(s):  
Olivia E Kaye ◽  
Paul Cook
Keyword(s):  
Renal Stones ◽  
Reference Interval ◽  
Reference Intervals ◽  
University Hospital ◽  
Specific Reference ◽  
Serum Samples ◽  
Rank Analysis ◽  
Local Reference ◽  
Local Determination

Background Method-dependent variation of caeruloplasmin measurement is significant and necessitates the requirement for assay-specific reference intervals. Local determination becomes necessary in the absence of suitable published or manufacturer-quoted reference intervals. Methods Applicability of the Beckman Coulter AU-quoted reference interval was determined by assay of 20 surplus serum samples from patients attending the medical renal stones clinic at University Hospital Southampton. Subsequently, 60 additional samples were collected for local reference interval determination. Samples were analysed for caeruloplasmin using the Beckman Coulter AU turbidometric kit on an AU680 analyser. Outliers were removed, and non-parametric rank analysis of the results was performed. Results The Beckman Coulter-quoted reference interval of 200–600 mg/L was unsuitable with 40% of the verification samples falling below 200 mg/L. A caeruloplasmin reference interval of 150–320 mg/L was established. Conclusion Users should be aware the quoted Beckman Coulter AU turbidometric reference interval may not be appropriate. We have established a method-specific adult reference interval for routine use.

Sign in / Sign up

Export Citation Format

Share Document