[27] Semiautomation of immunoassays by use of magnetic transfer devices

Smith, Kendall O.; Gehle, Warren D.

doi:10.1016/s0076-6879(80)70066-6

Cited by 8 publications

(4 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, although the temperature differences across a plate are to a great extent responsible for such inconsistencies as the edge effect which have been reported in the plate method (2,5,11), this thermal difficulty can be easily eliminated in the bead method by prewarming the reagents distributed in microplate wells and by a sensitization process in which many solid-phase units are totally immersed in the incubated antigen solution. Moreover, Smith and Gehle (20) have pointed out that the ELISA system with iron beads as the solid phase is superior to the bead method with other materials in that simultaneous processing is easily done by magnetic transfer devices. Synchronized incubation, as well as the uniform surface area of the solid phase (19), leads to high precision in the assay.…”

Section: Resultsmentioning

confidence: 99%

“…es: a magnet plate ELISA procedure. The test was performed essentialit ceramic magnets ly as described by Takeda (21) and Smith and Gehle bottom microplate, (19,20). The parameters and other basic conditions in a hole 3 mm in the assay were determined as described below.…”

Section: Methodsmentioning

confidence: 99%

“…The ELISA method with polycarbonate-coated iron beads as the solid phase and with a magnetic processing system was proposed by Smith and Gehle (19) and was afterward adapted for microtitration by the same authors (20). Some of its advantages over the other ELISA systems have been reported as (i) the uniformity in the surface area of the solid phase involved in the reaction, which is important for the precision of the assay, and (ii) the simplicity and economy of simultaneous processing with such a semiautomated system.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Reproducible enzyme-linked immunosorbent assay with a magnetic processing system for diagnosis of toxoplasmosis

Konishi¹,

Takahashi²

1983

J Clin Microbiol

View full text Add to dashboard Cite

An enzyme-linked immunosorbent assay with polycarbonate-coated iron beads as the solid phase and with magnetic processing devices was evaluated for the quantitation of antibodies to Toxoplasma gondii in human serum samples. Under the parameters and other basic conditions determined in this study, the assay was highly reproducible: coefficients of variation for the absorbance values obtained with the positive serum were 2.42% in same-day tests and 3.75% in day-today tests. Significant correlations were observed between the present assay system and other conventional serological tests: correlation coefficients were 0.960 with the dye test and 0.929 with the latex agglutination test. Statistical analysis based on the frequency distribution of absorbance values for dye-test-positive and dyetest-negative serum samples gave feasible border lines for distinguishing between positive and doubtful samples (0.357) and between doubtful and negative samples (0.266). Under this diagnostic criterion, the results of our assay system agreed remarkably well with those obtained by the dye test and the latex agglutination test, with consistencies of 94.9 and 93.9%, respectively.

show abstract

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Reproducible enzyme-linked immunosorbent assay with a magnetic processing system for diagnosis of toxoplasmosis

Konishi¹,

Takahashi²

1983

J Clin Microbiol

View full text Add to dashboard Cite

show abstract

“…The plate was then shaken dry, and the procedure was repeated. Polystyrene-coated steel beads were washed by the following procedure: a bead-transfer device (29) was placed over the Microtiter plate containing the beads, and when a ceramic magnet (29) was placed on the transfer device, the magnetic attraction allowed transfer of the beads to a clean Microtiter plate containing the wash reagent. The beads were remained in the reagent for 3 min with periodic agitation, and then the entire procedure was repeated.…”

Section: Antibody Concentrationmentioning

confidence: 99%

Enzyme-linked immunosorbent assay for detection of Staphylococcus aureus alpha-toxin

Surujballi¹,

Fackrell²

1984

J Clin Microbiol

View full text Add to dashboard Cite

A sandwich enzyme-linked immunosorbent assay was developed for measuring Staphylococcus aureus alpha-toxin. This assay was 500 to 1,000 times more sensitive than the commonly used hemolytic titration assay and was less variable. The binding of alpha-toxin to the adsorbed antibody was most effective after an overnight incubation at 27°C. The toxin was detectable even at a log2 17 dilution of an S. aureus culture supernatant. Staphylococcal alpha-toxin is generally measured by the hemolytic titration assay (8, 16, 22, 24, 39, 40). However, this assay has several disadvantages, such as variability (3, 7, 8, 14) and lack of standardization (25, 27), which limit its use as a quantitative method. The use of enzyme-labeled antibodies in the form of the enzyme-linked immunosorbent assay (ELISA) was pioneered by Engvall and Perlmann (18, 19) and Van Weemen and Schuurs (33, 34). Since its introduction, ELISA techniques have gained wide acceptance (1, 2, 6, 13, 15, 28, 30, 32, 37, 41) over the equally sensitive radioimmunoassay, for a number of reasons as reviewed by Wisdom (38) and O'Sullivan et al. (26). This paper describes the development of a double-antibody sandwich (35, 36) ELISA for the detection of the alphatoxin of Staphylococcus aureus Wood 46; this form of ELISA overcomes the limitations of the hemolytic titration assay. MATERIALS AND METHODS Production of alpha-toxin. The production of alpha-toxin by S. aureus Wood 46 has been described (24). The bacteria were grown under 10% carbon dioxide at 37°C in Dolman-Wilson medium (17) for 36 to 48 h. The culture was then centrifuged at 10,000 x g for 20 min, and the supernatant with alpha-toxin was stored at-20°C. Purification was achieved by adsorption chromatography on controlled pore glass (9). Toxoid. Purified alpha-toxin was rendered nonhemolytic by heating it at 60°C for 30 min. This material is referred to as toxoid in accordance with the terminology of Burnet (11). Production and purification of antisera. Antitoxin was produced by the method of Lo and Fackrell (24). New Zealand white rabbits were hyperimmunized by intravenous and subcutaneous injections of purified toxoid at a concentration of 2 mg/ml in phosphate-buffered saline (PBS). Booster doses were given every 3 days for 3 weeks, and the antisera were obtained 1 month after the last injection. Immunoglobulin G (IgG) was purified by ammonium sulfate fractionation followed by ion-exchange chromatography (12) and then dialyzed against coating buffer. Purity was established by the appearance of a single line when purified antitoxin was diffused against crude toxin. Protein determination. Protein concentrations were determined by the method of Bradford (10). Hemolytic titration. The 50%-endpoint method (40) was modified (24) for use with Microtiter plates (Cooke Labora-* Corresponding author. tory Products), by proportional reduction of the reagent volumes. From an S. aureus culture supernatant, 50 Il was serially diluted in 50 ,u of PBS in the Microtiter plate. A 50

show abstract

In vivo and in vitro comparison of fire ant venom and fire ant whole body extract

Strom¹,

Boswell²,

Jacobs³

1983

Journal of Allergy and Clinical Immunology

View full text Add to dashboard Cite

[27] Semiautomation of immunoassays by use of magnetic transfer devices

Cited by 8 publications

References 59 publications

Reproducible enzyme-linked immunosorbent assay with a magnetic processing system for diagnosis of toxoplasmosis

Reproducible enzyme-linked immunosorbent assay with a magnetic processing system for diagnosis of toxoplasmosis

Enzyme-linked immunosorbent assay for detection of Staphylococcus aureus alpha-toxin

In vivo and in vitro comparison of fire ant venom and fire ant whole body extract

Contact Info

Product

Resources

About