PubMed Health⌕ Search

Biomedical subjects

K H Yeo

Publications and source records attributed to K H Yeo.

8 recordsLinked to original sources
PubMed1992

A competitive ELISA for lipoprotein(a).

A competitive ELISA for lipoprotein(a) (Lp(a)) is described. The method uses a commercially available polyclonal anti-Lp(a) antibody and an IgG biotinstreptavidin-horseradish peroxidase detection system. The method is simple and robust with an assay sensitivity of 0.7 ng/well (1.4 micrograms/l). The antibody cross-reactivity was 0.14% against LDL and 0.70% against plasminogen. The coefficients of variation obtained with control sera of 266 and 552 mg/l were: 5.0% and 4.6% (n = 6), respectively for the intraassay; and 10.8% and 9.5% (n = 16), respectively for the interassay. The method showed an excellent correlation with a commercial immunoradiometric assay (IRMA), y (ELISA) = 0.94x (IRMA) - 8, (r = 0.98). A recovery study in which a 200 mg/L standard and four plasma samples were diluted with different proportions of a low plasma sample, gave linear relationships and also confirmed the specificity of the antibody.

Binding, Competitive↗
PubMed1992

The use of enzyme-linked immunosorbent assay for the quantitation of Calloselasma rhodostoma (Malayan pit viper) venom and venom antibodies.

The specificity and sensitivity of an indirect and two (an 'ordinary' and a 'rapid') double sandwich enzyme-linked immunosorbent assay (ELISA) procedures for the quantitation of Calloselasma rhodostoma (Malayan pit viper) venom were examined. The three assays were equally sensitive and the accuracy of the assays was not substantially affected by individual variation in the venom composition. The specificity of the assays was examined against 26 venoms from snakes of the families Viperidae and Elapidae. While the double sandwich ELISA procedures were sufficiently specific to be used in the clinical immunodiagnosis of C. rhodostoma bite in Malaysia, the indirect ELISA procedure exhibited extensive cross-reactivity with other Malaysian pit viper venoms. Attempts were made to improve the specificity of the indirect ELISA procedure for the quantitation of C. rhodostoma venom. A 'low ELISA cross-reactivity' venom fraction (termed VF52) was isolated from C. rhodostoma venom by repeated Sephadex G-100 gel filtration chromatography. The indirect ELISA procedure using antibodies to VF52 as immunoreagent showed an improvement in specificity. The use of the indirect ELISA procedure for the detection of C. rhodostoma antibodies was also examined and the results show that the assay was sufficiently specific to be used for retrospective diagnosis of C. rhodostoma bite in Malaysia, in particular when VF52 was used as the coating antigen.

Antibody Specificity↗
PubMed1988

An automated solid-phase 17 alpha-hydroxyprogesterone ELISA method using a microtitre plate.

We report an automated ELISA method for the measurement of 17 alpha-hydroxyprogesterone in plasma samples. A rabbit antiserum raised against 17 alpha-hydroxyprogesterone-3-(O-carboxymethyl)oxime-bovine serum albumin is used for the assay and a homologous competitor 17 alpha-hydroxyprogesterone-3-(O-carboxymethyl)oxime-bovine thyroglobulin is coated onto a microtitre plate. A goat anti-rabbit IgG-horse radish peroxidase is used as a probe for this solid-phase assay. The assay exhibits good sensitivity, precision and accuracy. The method is used routinely for the management of patients with congenital adrenal hyperplasia.

17-alpha-Hydroxyprogesterone↗
PubMed1987

An enzyme-linked immunosorbent assay (ELISA) for plasma progesterone: immobilised antigen approach.

A single extraction ELISA for plasma progesterone is described using the fixed antigen approach. Progesterone is covalently coupled to bovine thyroglobulin and adsorbed onto a 96-well microtitre plate in guanidine hydrochloride. The assay, performed on an automatic ELISA processor, follows an established methodology used for other steroid hormones analysed in this laboratory with concomitant advantages in assay standardisation, cost structure and result throughput. A comparison with an established RIA shows the assay to be rapid, of similar specificity and accuracy with a sensitivity of less than 0.5 nmol/l and is suitable for use in a routine endocrine laboratory for determination of luteal function.

Animals↗
PubMed1986

A monoclonal antibody to prednisone: use of enzyme-linked immunosorbent assay (ELISA) for screening and characterization of antigenic determinants.

ELISA technology using immobilized steroid conjugates has allowed the rapid screening and characterization of hybridoma supernatants. Although cortisol-3CMO-BSA was the immunogen, a monoclonal antibody with exceptionally high cross-reactivity (greater than 1000%) to prednisone was obtained. Characterization of the antigenic determinants shows a requirement for overall glucocorticoid 21-hydroxyl and 17 alpha-hydroxyl groups with additional high specificity for the 1,2-double bond and 11-position. There is potential use for this antibody in the assay of prednisone.

Animals↗
PubMed1986

A competitive enzyme-linked immunosorbent assay for plasma 11-deoxycortisol (17,21-dihydroxy-4-pregnene-3,20-dione).

An enzyme-linked immunosorbent assay (ELISA) for 11-deoxycortisol is described for the first time. 11-Deoxycortisol-thyroglobulin conjugate is adsorbed onto the wells of a 96-well ELISA plate and competes with 11-deoxycortisol in the standards or plasma extract for antibody binding sites. After washing, immobilized primary antibody is probed with peroxidase-labeled goat anti-rabbit IgG. The ELISA plate is further washed and o-phenylenediamine added, color developed and the absorbance read at 492 nm. The ELISA shows good agreement with our existing 11-deoxycortisol radioimmunoassay (RIA) and has similar specificity and performance which allow its use in the routine steroid laboratory for assessing pituitary adrenal function by the metyrapone test.

17-Hydroxycorticosteroids↗
PubMed1985

125I radioimmunoassay for 17 alpha-hydroxyprogesterone in plasma, for diagnosing and managing congenital adrenal hyperplasia.

This rapid, inexpensive, and sensitive radioimmunoassay (RIA) for plasma 17 alpha-hydroxyprogesterone involves radioiodination. A single extraction with toluene/hexane removes an average 93% of the hormone from 0.1 mL of plasma. The extract is evaporated and the hormone is estimated by a simple, precise, and accurate 125I RIA involving a specific rabbit antiserum. A suspension of dextran-coated charcoal is used to separate free and bound steroid. Inter- and intra-assay CVs were less than 15 and less than 10%, respectively, and the sensitivity was 3 pg per assay tube. The regression equation for data on 17 alpha-hydroxyprogesterone added to steroid-free plasmas was y = 0.94x + 2.2 (r = 0.99). However, the turnaround time is only one-half to one-tenth that for most 3H RIA (3 h vs 6 to 30 h). The ranges of values found for plasma from normal subjects, treated and untreated patients with congenital adrenal hyperplasia, and infants with newly detected congenital adrenal hyperplasia were, respectively, 1 to 11, 0 to 20, 30 to 620, and 270 to 4900 nmol/L.

17-alpha-Hydroxyprogesterone↗