Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 1989 Sep;27(9):2008-13.
doi: 10.1128/jcm.27.9.2008-2013.1989.

Application of quantitative immunofluorescence to clinical serology: antibody levels of Toxoplasma gondii

D S Kaplan  1 , G L Picciolo
Affiliations

Application of quantitative immunofluorescence to clinical serology: antibody levels of Toxoplasma gondii

D S Kaplan et al. J Clin Microbiol. 1989 Sep.

Abstract

Methods currently used for immunofluorescent reagent standardization require subjective visual comparison of reagents with control materials. Reactivities of reagents in immunofluorescence test kits vary from manufacturer to manufacturer. To solve these problems, a quantitative immunofluorescence (QIF) method which uses a calibrated photometric system and incorporates reducing agents into the mounting medium to reduce fading was developed to replace the visual method of endpoint determination. A uranyl glass slide was used to calibrate the instrument's voltage measurements, permitting daily comparisons and measurement of the instrument reading fluctuations. The QIF method was initially tailored to the determination of serum antibodies to Toxoplasma gondii by measuring the fluorescence intensity of individual tagged organisms. The nonspecific fluorescence intensity resulting from the counterstain was eliminated by use of a red-suppressing filter. The dilution-correlated polar fluorescence component was removed by subtraction of the intensity for the matching negative control dilution from each sample dilution intensity. The QIF method showed a 94% correlation with the visual comparison method for 62 clinical specimens.

PubMed Disclaimer

Similar articles

See all similar articles

Cited by

References

    1. Adv Appl Microbiol. 1984;30:197-234 - PubMed
    1. J Clin Microbiol. 1987 Dec;25(12):2262-5 - PubMed
    1. Carcinogenesis. 1989 Apr;10(4):641-6 - PubMed
    1. J Clin Microbiol. 1989 Mar;27(3):442-7 - PubMed
    1. Exp Parasitol. 1971 Apr;29(2):197-200 - PubMed

LinkOut - more resources