Simple standardized enzyme-linked immunosorbent assay for human antibodies to Entamoeba histolytica

Self Cite

A normalized enzyme-linked immunosorbent assay for the determination of immunoglobulin G antibodies to cytomegalovirus is described. The rapid assay involves three 30-min incubations and permits the quantitation of antibody levels with a single-specimen dilution in conjunction with a reference antibody preparation. The results obtained with the normalized enzyme-linked immunosorbent assay correlated closely with the results of complement fixation titrations and another commercially available enzyme-linked immunosorbent assay. The specificity of the procedure was further demonstrated by viral absorption, using cytomegalovirus from two different sources and other viral antigen preparations, including rubella and influenza. The reproducibility of the normalized test results is good and allows for greater uniformity of reporting on a day-to-day basis, as well as between laboratories.

Section: Resultssupporting

confidence: 69%

Normalized enzyme-linked immunosorbent assay for determining immunoglobulin G antibodies to cytomegalovirus

Kiefer¹,

Phelps²,

Halbert³

1983

Self Cite

“…At the same time, when a large number of serum samples were titrated by both assays, scattering of ELISA titers was observed for each antitoxin value. Such scattering of ELISA values, in comparison with other assays based on stepwise titration methods, has been observed in several other complex antigen-antibody systems, for cytomegalovirus (4), rubella (6), Toxoplasma gondii (5), and Entamoeba histolytica (9).…”

Section: Discussionmentioning

confidence: 55%

Immunoenzymatic assay of anti-diphtheric toxin antibodies in human serum

Camargo¹,

Silveira²,

Furuta³

et al. 1984

An enzyme-linked immunosorbent assay was developed for measuring immunoglobulin G anti-diphtheric toxin antibodies in human serum. The assay was done in plastic plates coated with purified diphtheric toxoid. Since a straight-line relationship was found between logs of extinction values and of antibody concentrations, with a very constant slope, serum titers could be expressed as log1o of the serum dilution corresponding to a definite optical density, such as 0.5. The assay furnished highly reproducible titers on a continuous range, with coefficients of variation less than 10%. Only one or two serum dilutions were usually sufficient for serum titration. To establish correspondence of the enzyme-linked immunosorbent assay titers with biologically determined antitoxin international units, a regression equation was fitted between the respective values for 112 serum samples titrated in both tests. The enzyme-linked immunosorbent assay titer of 2.38 corresponded to an antitoxin titer of 0.01 U, which is considered as the minimal protective level. Simple to perform, economical, and precise, the immunoenzymatic assay seems to be a very practical procedure for seroepidemiological purposes.

“…The numerous advantages of methods that use an enzyme label have been pointed out (3,19). Our laboratories have developed a series of sandwich tests of the enzymelinked immunosorbent assay (ELISA) type for diagnostic purposes, which use covalent bonding onto small disks as the solid phase (4-10, [12][13][14][15][16][17][18]. These assays are all standardized, precise, and reproducible, and they were highly correlated with previously used procedures.…”

mentioning

confidence: 99%

Rapid dot enzyme immunoassay for the detection of antibodies to cytomegalovirus

Lin¹,

Halbert²

1986

Self Cite

Cytomegalovirus (CMV) antigen was coated onto a white opaque plastic card as small dots inside circles marked in the microtiter plate weUl pattern. The card with antigen dots could be cut according to the number of test samples to be assayed. Small drops of undiluted serum samples, goat antibodies to human immunoglobulin G labeled with alkaline phosphatase, and finally substrate (5-bromo-4-chloro-3-indolyl phosphate) were sequentially added to the antigen spots and incubated in the open air at room temperature for 5 min each. The antigen dots showed blue color for sera with immunoglobulin G antibodies to cytomegalovirus but no color for those without. The developed antigen dots could be rinsed with water and kept as permanent records. For the assay of a large number of serum samples, a modified procedure with serum diluted 1:10 and longer first two incubations (20 min each) was found to be more comfortable to perform. The results of this assay for 123 undiluted and 256 diluted serum samples revealed very good correlations with those obtained by a commercially available test kit for immunoglobulin G antibodies to cytomegalovirus with 97 and 99% agreement, respectively. This dot test was very reproducible and required no instrumentation. The reagents, including coated antigen dots, are stable at room temperature for at least 2 months and are ready for use.