Highly Sensitive Sandwich Enzyme Immunoassay for Alpha-Fetoprotein in Human Saliva

1992 ◽  
Vol 29 (5) ◽  
pp. 519-522 ◽  
Author(s):  
Xian Yang Yio ◽  
Jing Jiang ◽  
Fen Zhi Yin ◽  
Ke-He Ruan
Keyword(s):  
Enzyme Immunoassay ◽  
Human Saliva ◽  
Minimum Detectable Concentration ◽  
Igg Antibody ◽  
Coefficients Of Variation ◽  
Highly Sensitive ◽  
Detectable Concentration ◽  
Polystyrene Plate ◽  
Normal Human ◽  
Sandwich Enzyme Immunoassay

To determine α-fetoprotein (AFP) in human saliva, a highly sensitive sandwich enzyme immunoassay for saliva AFP was developed. AFP standards and saliva samples were added into the wells of a polystyrene plate coated with goat IgG antibody against human AFP. After incubation, the wells were washed and horseradish peroxidase-labelled antibody was added. The enzyme activity specifically bound to the well was assayed using 3,3′,5,5′-tetramethylbenzidine and hydrogen peroxide as substrate. The reaction was stopped by addition of 2 M sulphuric acid and the AFP concentration was determined from the absorbance at 450 nm. The minimum detectable concentration was 8 ng/L. The recovery of AFP mixed with human saliva was 91·1–102·4%. The within-assay and between-assay coefficients of variation were 6·5–8·9% and 7·6–10·8%, respectively. The assay correlated well with a radioimmunoassay for human AFP ( r = 0·985, n = 13, P < 0·001). The mean concentration of AFP in normal human saliva was 14·3 ng/L (SEM = 4·9 ng/L, n = 10) and significantly higher levels of saliva AFP were observed in hepatocellular carcinoma patients with positive serum AFP (mean 1367·8 ng/L, SEM 595·4 ng/L, n = 6; P < 0·001). Strong correlation was observed between saliva AFP and serum AFP ( r = 0·978, P < 0·01, n = 13).

A highly sensitive sandwich enzyme immunoassay of urinary growth hormone in children with short stature, Turner's syndrome, and simple obesity

1989 ◽  
Vol 121 (4) ◽  
pp. 513-519 ◽  
Author(s):  
Hiroshi Tomita ◽  
Masamichi Ogawa ◽  
Takashi Kamijo ◽  
Osamu Mori ◽  
Eiji Ishikawa ◽  
...  
Keyword(s):  
Short Stature ◽  
Enzyme Immunoassay ◽  
Gh Deficiency ◽  
Urine Samples ◽  
Turner's Syndrome ◽  
Turner’S Syndrome ◽  
Highly Sensitive ◽  
Significant Difference ◽  
Simple Obesity ◽  
Sandwich Enzyme Immunoassay

Abstract. GH values were determined by a highly sensitive sandwich enzyme immunoassay in the 1st morning and/or 24-h accumulated urine samples in 94 children (short stature 70, including 14 with complete GH deficiency, 9 with partial GH deficiency, and 47 with GH-normal short stature; Turner's syndrome, 10, and simple obesity, 14). GH values were also determined in the 2nd to 4th urine samples taken on the same day together with the 1st morning urine in 5 of them. GH values in the 1st morning urine correlated significantly with those of the 24-h urine and with serum peak and mean GH values during nocturnal sleep as a physiological GH secretion test. The 2nd to 4th urines had lower GH concentrations than the 1st morning urine. The GH value of the 1st morning urine in complete GH deficiency was significantly lower than those in GH-normal short stature, partial GH deficiency and Turner's syndrome. However, no significant difference was detected in urinary GH values between complete GH deficiency and simple obesity. We conclude that 1st morning urinary GH estimation may be useful for differentiation of complete GH deficiency from other causes of short stature, but may be difficult for the distinction between complete GH deficiency and obesity with normal GH secretory ability.

Dissociation of mannan--serum complexes and detection of Candida albicans mannan by enzyme immunoassay variations.

1982 ◽  
Vol 28 (2) ◽  
pp. 306-310 ◽  
Author(s):  
E Reiss ◽  
L Stockman ◽  
R J Kuykendall ◽  
S J Smith
Keyword(s):  
Candida Albicans ◽  
Enzyme Immunoassay ◽  
Alkali Treatment ◽  
Human Sera ◽  
Normal Human ◽  
Sandwich Enzyme Immunoassay ◽  
Antigen Antibody ◽  
Bead Method

Abstract Candida albicans mannan was added to normal human sera and the resulting complexes were dissociated by boiling (boil) with EDTA or by alkali treatment (bead method). The mannan released was detected by "sandwich" enzyme immunoassay (EIA) or by EIA inhibition. Each EIA took 2.3 h to perform. The total time for the boil-EIA combination was 2.7 h and for the bead-EIA, 3.8 h. The temperature favorable for antigen--antibody incubation was 4 degrees C. The sandwich EIAs were preferable to EIA inhibition because absorbance was directly proportional to mannan concentration, within-run variation was decreased, and accuracy was increased. The boil-sandwich EIA had the highest sensitivity in the 12.5 to 200 micrograms/L range.

Specific enzyme immunoassay for human chorionic gonadotrophin

1981 ◽  
Vol 97 (4) ◽  
pp. 562-568 ◽  
Author(s):  
Tatsuhiro Sekiya ◽  
Yoshihito Furuhashi ◽  
Setsuko Goto ◽  
Shigeaki Kaseki ◽  
Yutaka Tomoda ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Solid Phase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Serum Samples ◽  
Coefficients Of Variation ◽  
Highly Sensitive ◽  
Assay Tube ◽  
Sandwich Type ◽  
Serial Samples

Abstract. A sandwich-type enzyme immunoassay system specific for human chorionic gonadotrophin (hCG) was prepared with the antibody Fab'-β-D-galactosidase complex and the antibody F(ab')2-immobilized silicone rubber solid phase by using a purified antibody to β subunit of hCG (hCGβ). The assay system cross-reacted less than 4% with human luteinizing hormone (hLH) and human follicular stimulating hormone (hFSH), and proved to be highly sensitive with hCG measurable at levels as low as 0.3 mIU per assay tube. Using 50 μl of serum sample, 6–600 mIU/ml of hCG in serum could be determined specifically with the same degree of precision as in radioimmunoassay but without sample interference with the assay. The coefficients of variation within-run and between-run were 8.6–8.9%, and 4.9– 10.7%, respectively. Values obtained with the enzyme immunoassay correlated well with those of radioimmunoassay ([unk] = 0.98, slope = 0.94, y-intercept = 10.2 mIU/ml for 75 serum samples). Results of the immunoassay of hCG levels in serial samples of serum from healthy women and patients with choriocarcinoma show that this method is useful in the clinical diagnosis of trophoblastic disease.

Human growth hormone (hGH) in urine and its correlation to serum hGH examined by a highly sensitive sandwich enzyme immunoassay

1987 ◽  
Vol 162 (2) ◽  
pp. 229-235 ◽  
Author(s):  
Seiichi Hashida ◽  
Eiji Ishikawa ◽  
Yuzuru Kato ◽  
Hiroo Imura ◽  
Zen-ichi Mohri ◽  
...  
Keyword(s):  
Growth Hormone ◽  
Enzyme Immunoassay ◽  
Human Growth Hormone ◽  
Human Growth ◽  
Highly Sensitive ◽  
Sandwich Enzyme Immunoassay

Determination of Insulin in Human Saliva Using a More Sensitive Sandwich Enzyme Immunoassay

1988 ◽  
Vol 21 (3) ◽  
pp. 381-394 ◽  
Author(s):  
Ke-He Ruan ◽  
Dan-Ru Ke ◽  
Xiu-Wang Huang ◽  
Da-Ren Ni ◽  
Shi-Zhong Pan ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Human Saliva ◽  
Sandwich Enzyme Immunoassay

Variability in the adsorption properties of microtitre plates used as solid supports in enzyme immunoassay.

1980 ◽  
Vol 26 (6) ◽  
pp. 741-744 ◽  
Author(s):  
L J Kricka ◽  
T J Carter ◽  
S M Burt ◽  
J H Kennedy ◽  
R L Holder ◽  
...  
Keyword(s):  
Enzyme Immunoassay ◽  
Adsorption Properties ◽  
Individual Sample ◽  
Microtitre Plate ◽  
Enzyme Protein ◽  
Solid Supports ◽  
Protein Conjugates ◽  
Adsorbed Protein ◽  
Coefficients Of Variation ◽  
Sandwich Enzyme Immunoassay

Abstract We evaluated the variability in the amount of protein adsorbed onto the surface of individual wells of an assortment of microtitre plates by use of procedures involving enzyme-protein conjugates. Coefficients of variation in adsorbed protein ranged from 5.2 to 29.5%. Microtitre plates show a distinct “edge effect”; wells at the edges of a plate adsorb more protein than those in the interior, which markedly affects results from immunoassays involving such plates. In a sandwich enzyme immunoassay the results for an individual sample varied by +/− 18%; in a competitive assay, values read from different calibration curves in the same plate varied by +/− 11%. Scanning electron microscopy and birefringence studies demonstrated no marked physical differences between individual wells on a plate. The variability in the amount of protein adsorbed onto the surface of individual wells on the same microtitre plate seriously affects the reliability and interpretation of results of immunoassays in which such plates are used as solid supports.

Competitive particle concentration fluorescence immunoassay for measuring 5,10-dideaza-5,6,7,8-tetrahydrofolic acid (lometrexol) in serum

1991 ◽  
Vol 37 (2) ◽  
pp. 254-260 ◽  
Author(s):  
Larry D Taber ◽  
Peter O'Brien ◽  
Ronald R Bowsher ◽  
J Richard Sportsman
Keyword(s):  
Particle Concentration ◽  
Cross Reactivity ◽  
Minimum Detectable Concentration ◽  
Fluorescence Immunoassay ◽  
Standard Curve ◽  
Coefficients Of Variation ◽  
Analytical Recovery ◽  
Detectable Concentration ◽  
Tetrahydrofolic Acid ◽  
Cancer Agent

Abstract A competitive particle concentration fluorescence immunoassay (PCFIA) is described for measuring 5,10-dideaza-5,6,7,8-tetrahydrofolic acid (lometrexol; Lilly) in human serum. b-Phycoerythrin-labeled lometrexol competes with free lometrexol for binding to a limiting concentration of lometrexol-specific antibodies immobilized by a second antibody to submicrometer-diameter polystyrene particles in specially designed 96-well plates. Reaction particles are washed and concentrated onto filter membranes in the wells of the plates and the fluorescence is measured at 575 nm. The method, including sample preparation and data reduction, is automated and can be completed in less than 2 h. The assay has a standard curve maximum measurable concentration of 1000 micrograms/L and a minimum detectable concentration of 0.1 microgram/L. Analytical recovery of lometrexol in serum is quantitative at concentrations greater than 1 micrograms/L. Intra- and interassay coefficients of variation at 50 micrograms/L in serum are 7.1% (n = 9) and 7.5% (n = 33), respectively. The cross-reactivity of naturally occurring folates, folic acid analogs, and the anti-cancer agent methotrexate is minimal. We report the use of the PCFIA during Phase I clinical studies designed to evaluate the pharmacokinetics of lomextrexol after intravenous administration to cancer patients.

Sign in / Sign up

Export Citation Format

Share Document