Additional reagents for determination of acute infections

IgG absorption

IgG absorption
  • Before a patient's serum is tested for specific antibodies of the IgM class, antibodies of class IgG must be removed, for example by immunoabsorption.
  • Specifically bound IgG would displace IgM from the antigen leading to false IgM negative test results.
  • Moreover, the absorption prevents any IgM class rheumatoid factors present from reacting with specifically bound IgG and thus leading to false IgM positive test results.
  • Indication: an IgG absorption of serum samples should always be performed for all IgM antibody determinations in infectious serology before incubating the sera.
  • IgG/RF absorbent is contained in the sample buffer in all ELISAs for infectious serology (class IgM).

EUROSORB IgG/RF absorbent for indirect immunofluorescence

EUROSORB IgG/RF absorbent
  • Functional principle: the EUROSORB reagent contains an anti-human IgG antibody preparation from goat. Immunoglobulin G of a serum or plasma sample is bound with high specificity by these antibodies and precipitated. If the sample also contains rheumatoid factors, these will be absorbed by the anti-human IgG/IgG complex.
  • Incubation time of the sample with the reagent is 15 minutes.
  • All IgG subclasses are bound and precipitated by the anti-human IgG antibodies.
  • Human serum IgG in concentrations of up to 15 mg/ml and rheumatoid factors are completely removed by the absorbent (average serum IgG concentration in adults: 12 mg/ml).
  • The recovery rate of the IgM fraction is almost 100%.
  • One unit contains 4.5 ml absorbent, sufficient for the absorption of 100 serum samples.

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Urea solution, avidity buffer 1

Urea solutions and avidity buffers for the determination of low-avidity antibodies in infectious serology

  • To identify low-avidity antibodies in a patient’s serum, two immunofluorescence tests are performed in parallel: one test is carried out in the conventional way, the other one includes urea treatment between incubations with patient’s serum and peroxidase-labelled anti-human IgG, resulting in the detachment of low-avidity antibodies from the antigens.
  • Low-avidity antibodies are present if the fluorescence intensity is significantly reduced (two intensity levels or more) by urea treatment.
  • The following reagents for avidity determination are available:
 IFT, ab against  Order number  Avidity solution  Inc. time
Rubella virusZF 1130-0501urea solution, 5 M10 min
WNVZF 1130-0601urea solution, 6 M10 min
T. gondiiZF 1130-0801urea solution, 8 M10 min
EBV-EA, EBV-CAZF 1130-0801urea solution, 8 M30 min
CMVZF 1131-0101-1avidity buffer 110 min
VZVZF 1131-0101-2avidity buffer 230 min

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