Development of Reference Sediment Samples for Solid Phase Toxicity Screening Tests

1996 ◽  
Vol 56 (5) ◽  
pp. 696-702 ◽  
Author(s):  
K. K. Kwan ◽  
B. J. Dutka
Keyword(s):  
Solid Phase ◽  
Screening Tests ◽  
Toxicity Screening ◽  
Sediment Samples ◽  
Reference Sediment

scholarly journals False Positivity in a Cyto-ELISA for Anti-Endothelial Cell Antibodies Caused by Heterophile Antibodies to Bovine Serum Proteins

2000 ◽  
Vol 46 (2) ◽  
pp. 273-278 ◽  
Author(s):  
Ronan Revelen ◽  
Anne Bordron ◽  
Maryvonne Dueymes ◽  
Pierre Youinou ◽  
Josiane Arvieux
Keyword(s):  
Endothelial Cell ◽  
Bovine Serum ◽  
Serum Proteins ◽  
Solid Phase ◽  
Calf Serum ◽  
Blocking Agent ◽  
Screening Tests ◽  
Tween 20 ◽  
Serum Samples ◽  
Antibody Absorption

Abstract Background: ELISAs with fixed endothelial cells or cell lines are widely used screening tests for anti-endothelial cell antibodies (AECAs), but spurious increases occur. We examined interferences by heteroantibodies and means to eliminate them. Methods: AECAs were measured by ELISA on fixed layers of the human endothelial cell line, EA.hy 926, in a panel of 60 patient serum samples diluted in bovine serum albumin. Heteroantibodies against fetal calf serum (FCS) proteins were demonstrated and characterized in an ELISA—the interference assay—that used FCS-coated plates and Tween 20-containing buffer as blocking agent and sample diluent, as well as by immunoblotting. Results: In 12 of 60 patient serum samples, spurious increases of AECA titers were produced by endogenous antibodies reacting with FCS proteins from culture medium that were coated onto the solid-phase at the time of cell plating. This mechanism of interference was supported experimentally by exposing extracellular matrix, varying cell density, and incubating wells with FCS alone. The heterophile antibodies were mainly IgG and IgA, and in inhibition experiments, they recognized serum proteins from goat, sheep, and horse. Washing cells free of FCS before plating, or adding FCS (100 mL/L) to the patient sample diluent eliminated spurious signals from all 30 tested sera, but the latter method had practical advantages. Conclusions: Antibodies against animal serum proteins are a frequent cause of erroneous results in cyto-ELISAs. The interference can be eliminated by simple antibody absorption in FCS-containing dilution buffer.

Preparation of Milk Samples for Immunoassay and Liquid Chromatographic Screening Using Matrix Solid-Phase Dispersion

1994 ◽  
Vol 77 (4) ◽  
pp. 848-854 ◽  
Author(s):  
Steven A Barker ◽  
Austin R Long
Keyword(s):  
Solid Phase ◽  
Screening Tests ◽  
Dairy Production ◽  
Milk Samples ◽  
Matrix Solid Phase Dispersion ◽  
Phase Dispersion ◽  
Negative Results ◽  
Microbial Inhibition ◽  
Receptor Assays ◽  
Liquid Chromatographic

Abstract The use of drugs to maintain the health and maximize the output of dairy cattle has made the monitoring of milk for such agents essential. Screening tests based on immunological, microbial inhibition, and bacterial receptor assays have been developed for the detection of violative levels of therapeutic substances. However, such assays are not infallible, and false positive or negative results can occur when contaminants bind receptors or compete for the binding of the target residues. Such effects may arise from dietary sources, diseases, or other variables. Thus, a violation by such a test is not definitive until further confirmation is obtained. Our laboratory has developed extraction procedures for several drugs used in dairy production. Our method uses matrix solid-phase dispersion (MSPD) to isolate drugs away from contaminants and to eliminate many possible interferences. MSPD can also be used to enhance the specificity of such assays by fractionating various classes of drugs that may cross-react. Similarly, such methods may be used for liquid chromatographic screening and confirmation of a suspect sample.

In vitro toxicity screening tests: A comparison of activation systems and treatment protocols among different laboratories

1983 ◽  
Vol 8 (1) ◽  
pp. 7-11 ◽  
Author(s):  
Sabine H. H. Swierenga ◽  
David E. Amacher ◽  
Robert T. Christian ◽  
Joanne T. Emerman ◽  
Linda B. Jacobsen ◽  
...  
Keyword(s):  
Screening Tests ◽  
In Vitro Toxicity ◽  
Toxicity Screening ◽  
Treatment Protocols

scholarly journals Ash pollen allergy and aerobiology

2019 ◽  
Vol 28 (7) ◽  
pp. 289-298 ◽  
Author(s):  
Markus Gassner ◽  
Peter Schmid-Grendelmeier ◽  
Bernard Clot
Keyword(s):  
School Children ◽  
Solid Phase ◽  
Birch Pollen ◽  
Pollen Allergy ◽  
Fraxinus Excelsior ◽  
Screening Tests ◽  
Fraxinus Americana ◽  
Ash Dieback ◽  
Pollen Emission ◽  
Pollen Concentrations

Abstract Background Allergy to ash pollen is common in some parts of Europe. Sensitization is overlooked if Oleaceae pollen allergens are not included in screening tests. Methods Between 1983 and 2007, sensitization to aeroallergens was systematically investigated using serological methods in 15-year-old school children (Immuno-CAP [carrier polymer] test). Samples from 1986 and 2006 were also tested using the immuno-solid-phase allergen chip (ISAC) assay. School children with sensitizations in 1986 were retested in 2010. Airborne pollen concentrations were determined by the Swiss pollen measuring network. Results Sensitization (>0.7 kU/l) to ash pollen (Fraxinus americana t15)—16.3% (102/627)—was more frequent than to birch pollen (Betula verrucosa t3): 15.3% (96/627). ISAC assays performed in children in 1986 and 2006 revealed higher molecular seroprevalence for nOle e 1 (15%; 15/100) compared to rBet v 1 (12%; 12/100). Followed-up subjects (age, 39) showed an increase in sensitizations to ash pollen. IgE levels to pollen from indigenous ash (Fraxinus excelsior t25) were higher than to pollen from American ash (Fraxinus americana t15). Low ash pollen emission levels were recorded at all measuring sites in Switzerland every 2–4 years. The infection of ashes by Chalara fraxinea resulted in increased emission of ash pollen. Conclusion Symptoms in individuals sensitized to ash pollen vary according to the pollen count and may be masked by pollen from other trees that flower at the same time of year. Sensitization to ash/Ole e 1 can be higher than to birch/Bet v 1. The determination of IgE to common ash (Fraxinus excelsior) is more sensitive than to American ash (Fraxinus americana). Ash dieback due to Chalara appears to increase pollen emission. Allergies to ash pollen can be significantly underestimated due to a failure to (correctly) identify them; they can also be masked by other pollen families (birch). Harmful organisms such as Chalara can intensify pollen emissions at least temporarily.

Toxicity Screening Tests for Wastewater Treatment Plants – I

2005 ◽  
Vol 277-279 ◽  
pp. 559-568
Author(s):  
Jin Hwa Park ◽  
Yong Woo Yl
Keyword(s):  
Electron Transfer ◽  
Wastewater Treatment Plants ◽  
Domestic Wastewater ◽  
Strong Relationship ◽  
Domestic Sewage ◽  
Screening Tests ◽  
Toxicity Screening ◽  
Trickling Filter ◽  
Home Life ◽  
Wastewater Samples

Toxicity screening tests using the Reserve Electron Transfer (RET) and Electron Transfer (ETr) assays were performed with five wastewater samples amended with trickling filter (TF) or activated sludge (AS) biomass. In the case of untreated samples, Home Life domestic wastewater (HLD/W) showed the lowest inhibition, followed by domestic sewage (DS), hospital wastewater (H/W), East Straus wastewater (ES/W), and Mills wastewater (M/W) from both ETr and RET assays. After 12 hours of treatment at 20°C, DS with AS biomass had the lowest % inhibition from the RET assay, followed by DS with TF, HLD/W with TF, H/W with TF, M/W with TF, and M/W with AS. AS biomass reduced more toxicity from DS than TF biomass whereas acclimated TF biomass reduced significantly more toxicity than AS biomass, indicating the importance of acclimation. M/W was most toxic and resistant to biodegradation among six wastewater samples. No nitrification occurred with M/W and ES/W. While there was significant nitrification with DS treated by AS biomass, little nitrification by TF biomass occurred even with DS, HLD/W, and H/W. It appears that nitrification is significantly inhibited by M/W and ES/W even when mixed with domestic sewage. It appears that there is a strong relationship between the TIC/TC ratio and % inhibition.

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