Immunoradiometric assay with use of magnetizable particles: measurement of thyrotropin in blood spots, to screen for neonatal hypothyroidism.

1986 ◽  
Vol 32 (10) ◽  
pp. 1966-1968 ◽  
Author(s):  
K V Waite ◽  
G F Maberly ◽  
G Ma ◽  
C J Eastman
Keyword(s):  
Incubation Time ◽  
Separation Procedure ◽  
Immunoradiometric Assay ◽  
Assay Sensitivity ◽  
Neonatal Hypothyroidism ◽  
Blood Spots ◽  
Standard Curve ◽  
Coefficients Of Variation ◽  
Specialized Equipment ◽  
Short Incubation Time

Abstract We adapted a commercial immunoradiometric assay (IRMA) to measure thyrotropin in filter-paper blood spots. Two 3-mm blood spots are used for each standard and sample. These are incubated for 2 h with radiolabeled antibody and for 30 min with magnetic antibody, followed by a 10-min separation procedure. Assay sensitivity is 6 milli-int. units/L. Coefficients of variation (precision profile of the standard curve) ranged from 4.3 to 9.6%. The coefficient of correlation (r) between thyrotropin concentrations in the blood spots and in serum was 0.93. Pre-elution of the blood spots is necessary for short incubation time. Short incubation time, little need for specialized equipment, the high precision and sensitivity characteristic of IRMA, and ease of collection, transport, and storage of the blood-spot samples make this assay suitable for neonatal hypothyroid screening.

Immunoradiometric assay of atrial natriuretic peptide in unextracted plasma

1990 ◽  
Vol 36 (6) ◽  
pp. 855-859 ◽  
Author(s):  
J E Tattersall ◽  
A Dawnay ◽  
C McLean ◽  
W R Cattell
Keyword(s):  
Atrial Natriuretic Peptide ◽  
Natriuretic Peptide ◽  
Normal Subjects ◽  
Disulfide Bridge ◽  
Immunoradiometric Assay ◽  
Assay Sensitivity ◽  
Standard Curve ◽  
Hook Effect ◽  
C Terminus ◽  
Atrial Natriuretic

Abstract We have developed and validated a two-site liquid-phase immunoradiometric assay (IRMA) of atrial natriuretic peptide (ANP) in unextracted human plasma. Both radiolabeled rabbit anti-ANP IgG and polyclonal mouse anti-ANP must bind to ANP for detection, and the assay is specific for peptides with both an intact C-terminus and a disulfide bridge. The assay sensitivity (detection limit) is 0.96 pmol/L, and the working range is 2.3-300 pmol/L, with the hook effect occurring above 500 pmol/L. Results for diluted plasma from normal subjects and from patients with renal failure paralleled the standard curve; analytical recovery of ANP added to such samples averaged 94%. The between- and within-assay CVs at 8 pmol/L were 10% and 5%, respectively. The assay is sufficiently sensitive and precise to detect the postural change in ANP concentrations in normal subjects.

Immunoradiometric assay of carcinoembryonic antigen with use of avidin-biotin labeling.

1989 ◽  
Vol 35 (4) ◽  
pp. 573-576 ◽  
Author(s):  
J Peters ◽  
H Schmidt-Gayk ◽  
B Peters ◽  
F P Armbruster ◽  
A Quentmeier ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Carcinoembryonic Antigen ◽  
Dose Response ◽  
Response Curve ◽  
Tube Wall ◽  
Immunoradiometric Assay ◽  
Large Molecules ◽  
Standard Curve ◽  
Coefficients Of Variation ◽  
Biotin Labeling

Abstract In evaluating an enzyme-linked immunoassay of carcinoembryonic antigen (CEA) we found that the IgG fraction of polyclonal anti-CEA antibodies (DAKO) bound very well to the walls of polypropylene test tubes. We therefore developed an immunoradiometric CEA assay based on this binding of polyclonal anti-CEA antibody. We biotinylated a commercially available monoclonal antibody (Hybritech) and bound this to the CEA-anti-CEA bound to the tube wall. For detection we used 125I-labeled streptavidin. In comparison with several immunoassays for CEA this system offered several advantages such as greater linearity of the standard curve (from 0 to 74 micrograms/L), a steeper dose-response curve, and smaller coefficients of variation in the clinically useful range. This assay system may be used for other large molecules, so that only one tracer, the 125I-labeled streptavidin, has to be labeled; thus the technique seems suited for several different assays.

A solid-phase enzymeimmunoassay for the determination of progesterone in bovine, porcine and ovine plasma

1995 ◽  
Vol 75 (4) ◽  
pp. 525-529 ◽  
Author(s):  
R. P. Del Vecchio ◽  
W. D. Sutherland ◽  
M. L. Connor
Keyword(s):  
Bovine Serum Albumin ◽  
Serum Albumin ◽  
Petroleum Ether ◽  
Bovine Serum ◽  
Solid Phase ◽  
Plasma Samples ◽  
Assay Sensitivity ◽  
Coefficients Of Variation ◽  
Rabbit Igg

The purpose of this project was to develop a valid quantitative enzymeimmunoassay (EIA) for progesterone in blood plasma of cattle, pigs and sheep. Rabbit anti-progesterone, mouse monoclonal anti-rabbit IgG, authentic progesterone, and acetylcholine esterase bound covalently to progesterone were the principal reagents used to develop the EIA. Ninety-six well microliter plates were coated with mouse monoclonal anti-rabbit IgG and saturated with bovine serum albumin before use. Rabbit anti-progesterone was diluted to a working dilution of 1:2.0 × 106. Standard curves were linear and ranged from 1.56 to 400 pg of progesterone per well which allowed for the measurement of 0.03125 to 8.0 ng mL−1. Assay sensitivity averaged 1.56 pg well−1. Progesterone was extracted from plasma samples with petroleum ether. Plasma samples (n = 3 or 4 from each species) with unknown amounts of progesterone that were extracted and serially diluted with EIA buffer did not deviate from parallelism with progesterone standard curves in buffer. The correlation between EIA and radioimmunoassay (RIA) measurements of progesterone in the same plasma samples was high (P < 0.0001) for all three species (r = 0.96 for bovine; r = 0.96 for porcine; r = 0.94 for ovine). The regression of EIA data on RIA data produced the following equations:[Formula: see text]The intra- and inter-assay coefficients of variation were 5.4 and 10.6% for bovine, 5.8 and 11.0% for porcine and, 6.1 and 12.3% for ovine, respectively. These data show that this EIA is a valid and reliable memod for quantitating progesterone in extracts of bovine, porcine and ovine plasma. Key words: Enzymeimmunoassay, progesterone, plasma, bovine, porcine, ovine

Use of Iron Milk Medium for Enumeration of Clostridium perfringens

1982 ◽  
Vol 65 (5) ◽  
pp. 1129-1133 ◽  
Author(s):  
William D St John ◽  
Jack R Matches ◽  
Marleen M Wekell
Keyword(s):  
Clostridium Perfringens ◽  
Incubation Time ◽  
Incubation Temperature ◽  
Egg Yolk ◽  
Most Probable Number ◽  
Biochemical Tests ◽  
Probable Number ◽  
Large Numbers ◽  
Whole Milk ◽  
Short Incubation Time

Abstract A simple iron milk medium was used for isolation and enumeration of Clostridium perfringens from soil, sludge, and water samples. The whole milk contained only iron powder as a reducing agent; no other inhibitors were added. The iron milk most probable number (MPN) procedure was compared with 4 plating media: sulfite-polymyxin-sulfadiazine, Shahidi-Ferguson perfringens, tryptose-sulfite- cycloserine (both with and without egg yolk), and tryptone-sulfite-neomycin. The selectivity of the iron milk relies solely on the rapid growth of C. perfringens at 45°C and the stormy fermentation reaction within 18 h. Isolates were confirmed as C. perfringens by standard biochemical tests. The iron milk MPN procedure compared very well with the 4 plating media tested. Selectivity of incubation temperature, short incubation time, and ease of identification by the characteristic stormy fermentation make this method ideal for enumerating C. perfringens from large numbers of samples.

Simultaneous measurement of plasma apolipoproteins A-I and B by electroimmunoassay.

1982 ◽  
Vol 28 (1) ◽  
pp. 59-62 ◽  
Author(s):  
J C Fruchart ◽  
I Kora ◽  
C Cachera ◽  
V Clavey ◽  
P Duthilleul ◽  
...  
Keyword(s):  
Simultaneous Measurement ◽  
Apolipoprotein B ◽  
Secondary Standard ◽  
Plastic Film ◽  
Standard Curve ◽  
Atherosclerotic Lesions ◽  
Apolipoprotein A ◽  
Coefficients Of Variation

Abstract We describe a simplified electroimmunoassay for quantification of human apolipoproteins A-I and B on prepared plates. A solution of agarose at 55 degrees C, containing hydroxyethylcellulose and antibodies, is poured onto a plastic film and allowed to gel. Wells are punched in the gels and the plates are dried for storage. Before use, they are rehydrated and buffered. We use succinylated Sudan Black to prestain lipoprotein fractions of plasma. After electrophoresing samples of plasma or standards for 3 h at 4 degrees C at 12.5 V/cm, we measure the peak heights and read the results from a standard curve prepared by using calibrated sera of known apolipoprotein B and A-I content as secondary standard. The within- and between-assay coefficients of variation were less than 4% in all cases. Results correlated well with those obtained by classic electroimmunodiffusion. Subjects with confirmed atherosclerotic lesions had significantly (p less than 10(-9)) lower ratios of apolipoprotein A-I to apolipoprotein B, compared with ratios in controls.

Determination of nifedipine in serum or plasma by reversed-phase liquid chromatography.

1983 ◽  
Vol 29 (7) ◽  
pp. 1344-1348 ◽  
Author(s):  
P R Bach
Keyword(s):  
Liquid Chromatography ◽  
Reversed Phase ◽  
Extraction Column ◽  
Phase Extraction ◽  
Reversed Phase Liquid Chromatography ◽  
Ultraviolet Absorbance ◽  
Standard Curve ◽  
Coefficients Of Variation ◽  
Phase Liquid

Abstract Therapeutic concentrations of nifedipine in serum or plasma were measured by reversed-phase liquid chromatography, with detection by ultraviolet absorbance at 235 nm. In the procedure a disposable reversed-phase extraction column is used. A 1-mL sample is required. The method is sensitive to 3 micrograms of nifedipine per liter and the standard curve is linear to at least 400 micrograms/L. Coefficients of variation at 100 micrograms/L were 2.2% within-run, 2.8% between-run. The method has been used to determine nifedipine in patients involved in a test of its efficacy in treating muscular dystrophy.

Simplified Plate Diffusion System for Microbial Assays of Antibiotics

1987 ◽  
Vol 70 (4) ◽  
pp. 641-646
Author(s):  
Marietta Sue Brady ◽  
Stanley E Katz
Keyword(s):  
Diffusion System ◽  
Standard Curve ◽  
Single Plate ◽  
Accuracy And Precision ◽  
Coefficients Of Variation

Abstract A protocol for microbial assays of antibiotics, using the plate diffusion system, is presented. The system is based on the concept that a complete standard curve and assay unknowns can be placed on an issay plate and that 2 plates can be a complete assay with an accuracy and precision essentially equivalent to the official AOAC diffusion procedure. Four antibiotics, bacitracin, chlortetracycline, oxytetracycline, and streptomycin, were used in the design and comparison studies with the AOAC protocol. The coefficients of variation (CVs) for the AOAC design, using 10 replicates, ranged from 1.4 to 10.3% with a mean of 4.5%. The CVs for the single-plate option of the simplified design ranged from 4.3 to 9.6% with a mean of 6.6%; the CVs for the 2-plate option ranged from 2.5 to 6.8% with a mean of 43%; the CVs for the 3-plate option ranged from 1.2 to 5.0% with a mean of 3.0%.

Improved radioimmunoassay of urinary estriol.

1979 ◽  
Vol 25 (1) ◽  
pp. 99-102 ◽  
Author(s):  
M J Jawad ◽  
E A Wilson ◽  
H L Kincaid
Keyword(s):  
Incubation Time ◽  
Colorimetric Method ◽  
Detection Range ◽  
Standard Curve ◽  
Double Antibody ◽  
Analytical Recovery ◽  
Urinary Glucose

Abstract We report a rapid double-antibody radioimmunoassay for urinary estriol. Advantages over other current methods include: (a) 30-min hydrolysis; (b) total incubation time, 55 min; (c) assay unaffected by urinary glucose; (d) no degradation of estriol evident during hydrolysis; (e) superior (85%) analytical recovery of estriol conjugates; (f) linear standard curve by logit-log extrapolation; (g) good correlation (r = 0.83) with total estrogen determination by a generally accepted colorimetric method; (h) only 20 muL of urine required; and (i) the detection range is 1.9 to 100.5 mg/24-h urine.

Does cassava wastewater with a short incubation time affect soil organic carbon, microbial community and enzymatic activities?

CATENA ◽  
2018 ◽  
Vol 163 ◽  
pp. 354-360 ◽  
Author(s):  
Adriano dos Santos Moura ◽  
Erika Valente de Medeiros ◽  
Jéssica Emanuella da Silva Oliveira ◽  
Rafaela Felix da Franca ◽  
Anderson Dantas Lira ◽  
...  
Keyword(s):  
Microbial Community ◽  
Organic Carbon ◽  
Soil Organic Carbon ◽  
Incubation Time ◽  
Enzymatic Activities ◽  
Cassava Wastewater ◽  
Short Incubation Time

276. The technical and biological validation of an LH assay for use with the Western Grey Kangaroo (Macropus fuliginosis) and Black-flanked Rock Wallaby (Petrogale lateralis lateralis)

2008 ◽  
Vol 20 (9) ◽  
pp. 76
Author(s):  
P. Matson ◽  
C. Mayberry ◽  
N. Willers ◽  
M. A. Blackberry ◽  
G. B. Martin
Keyword(s):  
Plasma Concentrations ◽  
Standard Curve ◽  
Biological Validation ◽  
Grey Kangaroo ◽  
Coefficients Of Variation ◽  
Western Grey Kangaroo ◽  
Technical Validation ◽  
Zoo Biology ◽  
Smithsonian Institute ◽  
And Control

Methods for the measurement of marsupial LH invariably rely upon the similarity of the LH molecule between different species and usually use anti-ovine or anti-bovine LH antibody and an ovine or bovine labelled LH preparation. Initial attempts to measure plasma LH in the Western Grey Kangaroo with assays using antibodies to 4 different isoforms of ovine LH raised in 7 different rabbits were unsuccessful. An enzymeimmunoassay (EIA) developed for the Asian elephant (Zoo Biology 23:45–63) was then applied to the Western Grey Kangaroo and the Black-flanked Rock Wallaby. This EIA has an anti-bovine-LH monoclonal antibody (518B7 provided by Dr Jan Roser, University of California, Davis, USA), biotinylated ovine LH label and bovine LH standard (NIADDK-oLH-26 and NIH-bLH-B10, both provided by Dr Janine Brown and Nicole Abbondanza, Smithsonian Institute, Front Royal, Virginia USA). Technical validation showed that serial dilution down to 1:8 of plasma from 7 individuals of each species showed parallelism to the assay standard curve, and control samples (1.24–5.30 ng/mL) had between-assay coefficients of variation <9%. Biological validation was achieved by challenging animals with intramuscular GnRH (Fertagyl®, 2.5 µg/kg) and measuring LH before and 25 min after the injection. Significant increases in plasma concentrations of LH (mean ± sem; all P > 0.0005) were seen after GnRH for both the Western Grey Kangaroo (from 5.0 ± 0.8 ng/mL to 9.4 ± 1.2 ng/mL; n = 19) and the Black-flanked Rock Wallaby (from 6.0 ± 0.7 ng/mL to 10.6 ± 0.6 ng/mL; n = 28). In conclusion, this assay can be successfully used to measure LH in these two species.

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