Results 211 to 220 of about 144,715 (261)

Frequency of false‐negative reactions to the fragrance mix

Contact Dermatitis, 1993
To estimate the frequency of false‐negative‐ reactions to the fragrance mix, the 8 constituents of the mix in concentrations of 5% (2% for cinnamic aldehyde) were added to the European standard series for routine testing. Patients with positive reactions to individual ingredients in the absence of a reaction to the mix were retested with serial ...
Anton C De Groot, Th Van Joost, S Pavel   +2 more
exaly   +3 more sources

False Positive and Negative Hemoccult Reactions on a Normal Diet and Effect of Diet Restriction

Australian and New Zealand Journal of Medicine, 1980
Summary: False positive and negative hemoccult reactions on a normal diet and effect of diet restriction. M. L. Bassett and K. J. Goulston, Aust. N.Z. J. Med. 1980, 10. pp. 1–4.The reliability of Hemoccult, a guaiacimpregnated slide for detecting faecal occult blood, was assessed on both normal and restricted diets.
M L Bassett, K J Goulston
exaly   +3 more sources

False positive and false negative reactions in HLA B-27 antigen testing

Transfusion, 1979
The recent commercial availability of HLA B‐27 antiserum now enables laboratories without prior experience in HLA typing to test for this antigen. False positive and false negative reactions frequently occur and require judicious interpretation. In our laboratory, 30 of 100 specimens were positive for B‐27 and 70 were negative. Of the 30 positives, 10 (
exaly   +3 more sources

False negative and prozone reactions in tests for antibodies to Epstein-Barr virus-associated nuclear antigen

International Journal of Cancer, 1974
AbstractTitration of anti‐complementary human sera may yield false negative or prozone reactions in anti‐complement immunofluorescence (ACIF) tests for antibodies to Epstein‐Barr virus‐associated nuclear antigen (EBNA) when the human complement (C') is added to the serum dilutions prior to charging of the target cell smears (two‐stage ACIF test).
Werner Henle, Gertrude Henle
exaly   +3 more sources

False-Negative Reactions of the “Hemoccult” Slide Test

New England Journal of Medicine, 1978
K L, Cohen, E J, Luminati
exaly   +3 more sources

False-negative oxidase reaction as a result of medium acidification

Antonie van Leeuwenhoek, 1980
Acidification of the culture medium may lead to a false-negative result of the oxidase reaction. Hence, if the medium contained a carbon source or another component that is convertible to acid, a negative oxidase reaction should be considered inconclusive.
Havelaar, AHrivm, Hoogendorp, CJ, Wesdorp, AJ, Scheffers, WA   +3 more
openaire   +3 more sources

False Negative Reactions and Sensitivity in the Urine Glucose Oxidase Test

Diabetes, 1965
Some 6,217 random urine specimens were tested with both a glucose oxidase test (Combistix) and a copper reduction test (Clinitest). The ratio of positive Combistix to Clinitest was approximately 3 to 2. There were only eleven false negative enzyme paper tests.
R M, NAKAMURA, E B, REILLY, K, FUJITA, J, BROWN, G M, KUNITAKE   +4 more
openaire   +2 more sources

False negative hyperglucosuria test-strip reactions in laboratory mice

Laboratory Animals, 1982
Inhibition of a variety of commercial test strips for hyperglucosuria was experienced in laboratory mice. All mouse strains tested were found to have sufficiently high levels of ascorbic acid to cause inhibition, and male levels were higher than those of females. A regime to obtain optimum detection of positive results is discussed.
Taylor, D M, Neal, D L
openaire   +2 more sources

Degradation of triglycidyl isocyanurate as a cause of false‐negative patch test reaction

Contact Dermatitis, 2001
Triglycidyl isocyanurate (TGIC) is mainly used in polyester‐based powder paints, but also in laminates, insulating varnishes, coatings and adhesives. Several cases of contact allergy to TGIC have been reported during the last 10 years. Contact allergy to TGIC has developed in a factory producing the chemical, in a factory producing powder paints ...
U, Erikstam, M, Bruze, A, Goossens
openaire   +2 more sources

Overcoming false negatives due to the genomic context in polymerase chain reaction amplification

Journal of Biochemical and Biophysical Methods, 1999
In some instances defined genomic regions are so poorly amplified that they seem to be unamplifiable. A protocol was developed which allows good PCR amplifications by the use of restriction digestion combined with the elution of a pool of restriction fragments of defined size range from agarose gel after electrophoresis.
E, Baldrich, N, Xamena, O, Cabré
openaire   +2 more sources