New enzyme-linked immunosorbent assay for glycocalicin in plasma

1991 ◽  
Vol 37 (2) ◽  
pp. 169-172 ◽  
Author(s):  
ShinjI Kunishima ◽  
Klyotaka Hayashi ◽  
Sentaro Kobayashi ◽  
Tomokl Naoe ◽  
Ryuzo Ohno

Abstract A new sandwich-type enzyme-linked immunosorbent assay for quantifying glycocalicin, a proteolytic fragment of platelet membrane glycoprotein Ib, is described. The assay is based on the use of two monoclonal antibodies raised against glycoprotein Ib and involves the avidin-biotin technique. The detection limit is 7 micrograms/L and the range of glycocalicin determined in plasma is 0.01 to 1 mg/L. Assay time is 2 h. The intra-assay CV ranged from 3.6% to 5.2%, the interassay CV from 5.4% to 8.0%. Analytical recovery of purified glycocalicin added to a plasma pool averaged 96%. In 36 healthy subjects, the mean glycocalicin concentration in plasma was 0.36 (SD 0.07) mg/L (2.7 nmol/L). We conclude that this assay is suitable for measuring glycocalicin in plasma and is also more sensitive and precise than the previously published immunoassays based on competitive binding assay.

1988 ◽  
Vol 34 (4) ◽  
pp. 739-743 ◽  
Author(s):  
M Rosseneu ◽  
G Michiels ◽  
W De Keersgieter ◽  
J Bury ◽  
J P De Slypere ◽  
...  

Abstract A specific and sensitive "sandwich"-type enzyme-linked immunosorbent assay (ELISA) has been developed for quantifying human apo A-IV. Using apo A-IV immunosorbent columns, we isolated monospecific anti-apo A-IV antibodies for coating the ELISA plates and for preparing peroxidase-antibody conjugate. The assay can detect as little as 0.20 ng of apo A-IV, with mean intra- and interassay CVs of 3.6% and 8.2%, respectively. The apoA-IV concentrations in normolipemic and hyperlipemic plasma were unaffected by either delipidation or treatment with detergents or urea. To validate the ELISA assay we compared it with an immunoelectrophoretic technique. ApoA-IV concentrations in plasma from normo- and dyslipemic subjects compared well by the two assays (r = 0.89). The mean apo A-IV concentration, measured by ELISA in plasma from 50 normolipemic subjects, was 143 (SD 52) mg/L; values for dyslipemic subjects were not significantly different. We also used this new assay to monitor apo A-IV profiles of normolipemic and hypertriglyceridemic plasma after chromatographic fractionation.


1986 ◽  
Vol 32 (2) ◽  
pp. 265-270 ◽  
Author(s):  
J Bury ◽  
R Vercaemst ◽  
M Rosseneu ◽  
F Belpaire

Abstract We developed a sensitive, specific "sandwich"-type enzyme-linked immunosorbent assay in which affinity-purified antibodies are used for coating and also for preparing an antibody-peroxidase conjugate to quantify apolipoprotein E in serum and in its lipoprotein fractions. This technique is rapid (results within 5 h), precise (mean intra- and interassay CVs 4.3 and 8.2%, respectively), accurate, and simple to perform. Sample pretreatment did not enhance apo E immunoreactivity. For 47 normolipidemic subjects, the mean apo E concentration was 38.11 (SD 11.1) mg/L. Above-normal apo E concentrations were measured in all types of hyperlipoproteinemia, especially types III and V. Apo E correlated with triglyceride (r = 0.58) and cholesterol concentrations (r = 0.60). As determined by gel filtration, hypertriglyceridemia was associated with a redistribution of apo E towards the triglyceride-rich lipoprotein fractions, which contained 77.1% (SD 16.8%) of total plasma apo E in Fredrickson type V patients, compared with 12.5% (SD 6.3%) in normal persons.


1989 ◽  
Vol 35 (7) ◽  
pp. 1376-1379 ◽  
Author(s):  
T R Teni ◽  
A H Bandivdekar ◽  
A R Sheth ◽  
N A Sheth

Abstract This is a highly specific enzyme-linked immunosorbent assay (ELISA) for measuring prostatic inhibin-like peptide (PIP) in urine, in which we use penicillinase (EC 3.5.2.6) conjugated with PIP and, as solid phase, a polystyrene microtiter plate. We used this ELISA to measure PIP in 24-h urine specimens from men with prostatic cancer (PCa) and from age-matched controls. For prostatic cancer patients the mean +/- SEM urinary PIP of 36.1 +/- 5 micrograms/24 h was significantly (P less than 0.001) lower than the mean of 127.1 +/- 9 micrograms/24 h for the age-matched controls. PIP values for 30 samples measured by both ELISA and RIA correlated well (r = 0.985). We could detect as little as 1.56 ng of PIP in a sample. Analytical recovery of added PIP ranged from 91% to 104%. Mean CVs were 8.9% within-assay and 12.7% between-assay. We believe that this ELISA will be useful in assessing the status of PIP in men with normal and diseased prostates and in examining the function of the hypothalamus-pituitary-prostate axis.


1984 ◽  
Vol 30 (1) ◽  
pp. 149-151 ◽  
Author(s):  
S Lucertini ◽  
P Valcavi ◽  
A Mutti ◽  
I Franchini

Abstract This highly sensitive method for determining retinol-binding protein in human serum and urine is based on a double-antibody "sandwich"-type enzyme-linked immunosorbent assay. The assayable concentration range is 0.8-48 micrograms/L, the detection limit 0.2 micrograms/L. Within-assay coefficients of variation for 10 determinations at two different concentrations were 5.5 and 5.8%. The corresponding between-assay CVs were 7.9 and 9.2%. We saw no interference from any components of urine or serum. The mean urinary excretion by 30 healthy subjects, as determined by this method, was 101 micrograms/g of creatinine (SD 38.8). The concentration in serum averaged 43 mg/L (SD 12.1).


Author(s):  
J Grøndahl-HANSEN ◽  
N Agerlin ◽  
L S Nielsen ◽  
K Danø

An enzyme-linked immunosorbent assay (ELISA) was developed for the measurement of human urokinase-type plasminogen activator (u-PA) in plasma and serum. Microtiter plates were coated with a monoclonal antibody and incubated with standard or sample. Bound u-PA was quantitated with polyclonal antibodies conjugated with biotin, followed by avidin-peroxidase. The assay was 10-fold as sensitive as other previously reported ELISAs, the detection limit being approximately 1 pg of u-PA in a volume of 100 μl with a linear dose-response up to 15 pg of u-PA. The assay detected active u-PA and its inactive proenzyme form equally well and the recovery of both forms was higher than 90% in plasma. A variety of structurally related proteins, including t-PA, were tested, but no reaction with proteins other than u-PA and its amino-terminal degradation product were observed. The intra-assay and inter-assay coefficients of variation for determination of u-PA in plasma were 7.6% and 8.4%, respectively. The assay was equally applicable to serum. The values obtained with plasma and serum were similar, and the results were not affected by small variations in the preparation of the samples. The ELISA was used to measure the concentration of u-PA in plasma from 34 healthy donors. The mean values for u-PA in plasma from healthy donors was 1.1 ng/ml ± 0.3 ng/ml (SD) (range 0.6 - 1.5 ng/ml). No significant differences were found between men and women and no correlation between u-PA concentration and age could be demonstrated.The mean u-PA concentration in plasma from healthy donors obtained in this study is substantially lower than that reported by others. This might be due to different methods of determination of the protein content of the standard preparations or to differences in the specificity of the assays.


1988 ◽  
Vol 101 (2) ◽  
pp. 405-410 ◽  
Author(s):  
R. C. H Lau

SUMMARYEnzyme-linked immunosorbent assay (ELISA) tests were used to measure IgG antibody levels in 2638 New Zealand children who had been immunized with the triple vaccine DTP. The percentage of children immune to diphtheria decreased with age. The percentage of children immune to tetanus varied from 67.1 to 55.0%. The percentage of children with measurable antibody to pertussis increased with age. The mean percentages of children with measurable antibody or immunity to one or more DTP components were 34.2% (with 3 components), 34.4% (2 components), and 78.1% (1 component). It appears the immunization strategy for diphtheria and tetanus is satisfactory for herd immunity in New Zealand children. However, the current pertussis strategy may not be providing adequate immunity to 5-year-olds in this country.


Author(s):  
Jovana Matic ◽  
Jasna Mastilovic ◽  
Ivana Cabarkapa ◽  
Anamarija Mandic

Mycotoxins are toxic secondary metabolites of fungi that contaminate a large variety of foods and have toxic effects on humans. The best protection against mycotoxins is to monitor their presence in food. This paper shows the screening results of mycotoxins present in 76 samples of different groups of grain foods. Samples of grain food were analyzed for contamination with aflatoxins, ochratoxin A, zearalenone, fumonisins and deoxynivalenol. Analysis were conducted using competitive enzyme-linked immunosorbent assay (ELISA). None of the samples was contaminated with aflatoxins. The most predominant mycotoxin was ochratoxin A with the mean level of 4.84 ? 4.49 ppb in 19.7% of the examined samples. Zearalenone, fumonisins, and deoxynivalenol were found in 9.21, 14.5 and 3.9% of the samples, respectively. Mycotoxin content in the investigated samples was compared with the regulations of Serbia and those of the European Union.


1987 ◽  
Vol 70 (4) ◽  
pp. 657-661
Author(s):  
Titan S L Fan ◽  
Yi-Chun Xu ◽  
Fun Sun Chu

Abstract An indirect enzyme-linked immunosorbent assay (ELISA) for the detection of HT-2 toxin in the presence or absence of T-2 toxin is described. In the indirect ELISA, the relative cross-reactivities of antibodies against T-2 toxin (anti-T-2) with T-2 toxin and HT-2 toxin were 1 and 0.1, whereas anti-HT-2 cross-reactivities with T-2 toxin and HT-2 toxin were 0.33 and 1, respectively. Using such relationships, a formula was established that could be used to calculate the individual toxin concentration in a mixed sample after experimentally analyzing for T-2 and HT-2 toxins in the 2 indirect ELISAs. This method was tested by analyzing urine samples spiked with HT-2 toxin alone and samples spiked with both T-2 toxin and HT-2 toxin. A cleanup protocol for treatment of urine samples before ELISA was also established. The overall analytical recovery of HT-2 toxin when it was added at concentrations of 0.1-10 parts per billion (ppb) to the urine samples was ca 89%. When both T-2 and HT-2 toxins were added to the urine samples at equal concentrations of 0.5 to 5.0 ppb, their recoveries were 112 and 109%, respectively.


1991 ◽  
Vol 37 (10) ◽  
pp. 1742-1745 ◽  
Author(s):  
R Saïle ◽  
A Kandoussi ◽  
M Deveaux ◽  
J Descamps ◽  
E Hachulla ◽  
...  

Abstract This enzyme-linked immunosorbent assay procedure for quantifying serum amyloid P (SAP) in human plasma makes use of affinity-purified polyclonal antibodies to SAP in a "sandwich"-type format. The procedure is sensitive, reproducible, simple, and easily automatable. Results correlate well with those by a rocket immunoelectrophoresis method performed with the same antibodies. Sera from apparently normal individuals had a mean SAP content of 44.17 mg/L and increased with age.


2000 ◽  
Vol 12 (3) ◽  
pp. 245-252 ◽  
Author(s):  
Stewart W. Alcorn ◽  
Ronald J. Pascho

An enzyme-linked immunosorbent assay (ELISA) was developed on the basis of testing a single dilution of serum to quantify the level of antibody to the p57 protein of Renibacterium salmoninarum in sockeye salmon ( Oncorhynchus nerka). The levels of antibody were interpolated from a standard curve constructed by relating the optical densities (OD) produced by several dilutions of a high-titer rainbow trout ( O. mykiss) antiserum to the p57 protein. The ELISA OD values produced by as many as 36 test sera on each microplate were compared with the standard curve to calculate the antigen-specific antibody activity. Repeated measurements of 36 samples on 3 microplates on each of 6 assay dates indicated that the mean intraassay coefficient of variation (CV) was 6.68% (range, 0–23%) and the mean interassay CV was 8.29% (range, 4–16%). The antibody levels determined for the serum sample from 24 sockeye salmon vaccinated with a recombinant p57 protein generally were correlated with the levels determined by endpoint titration ( r2 = 0.936) and with results from another ELISA that was based on extrapolation of antibody levels from a standard curve ( r2 = 0.956). The single-dilution antibody ELISA described here increases the number of samples that can be tested on each microplate compared with immunoassays based on analysis of several dilutions of each test serum. It includes controls for interassay standardization and can be used to test fish weighing <3 g.


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