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           Search results for: Rabbit Anti-Nogo R Polyclonal Antibody, Biotin Conjugated   

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#10727257   2000/05/09 Save this To Up

Development of time-resolved immunofluorometric assays for rat follicle-stimulating hormone and luteinizing hormone and application on sera of cycling rats.

The aim of this study was to develop time-resolved immunofluorometric assays (TR-IFMA) for measuring rat (r)FSH and rLH. The advantages of these IFMAs are higher sensitivity due to lower background values, higher specificity as only intact molecules of FSH and LH can be measured, and a very long shelf life of the nonradioactive biotin antigens compared with radiolabeled iodine antigens. For rFSH, IFMAs are lacking, while for rLH, if present, the resources for antibodies are scarce or the mouse monoclonal antibodies (mMAbs) against LHalpha are inactive with FSH. Thus specific antibodies need to be obtained. With the final TR-IFMAs, rFSH and rLH levels were assessed during the estrous cycle and compared with those obtained with the more classical RIAs and fluoroimmunoassays (FIAs). Two IFMAs for rFSH were developed with mMAbs against the recombinant human (rec h)FSHbeta subunit (FSH56A) attached to the wall and two different rabbit polyclonal antibodies (PAbs) against the alpha subunit of rec hFSH (R93-2705) or recombinant rat (rec r)LH (R95-2715) conjugated with biotin as signal antibody. With both IFMAs, rFSH holo-molecules can be measured. Rat FSH standards could be assessed between 0.02 and 10 ng/ml with a detection limit of 0.05 and 0.24 ng/ml in buffer and serum, respectively. These detection limits in four IFMAs were 8- to 16-fold lower than those in RIAs and FIAs. This detection level allowed the measurement of FSH levels in serum of hypophysectomized (HYPEX) rats at 0.18 ng/ml. In serum of cycling rats, the FSH levels of the IFMA were 2-fold lower than those of the FIA, while in ovariectomized (OVX) rats the IFMA levels were comparable. A peak level of FSH was found during proestrus of Day 2 and gestation with both RIA and FIA, but with IFMAs at gestation only. An IFMA for rLH was set up with mMAb (hCG77A) reacting with rLHbeta as capture and rabbit PAb to rec rLHalpha (R95-2712) as signal antibody. Rat LH standard could be assessed between 0.001 and 10 ng/ml with a detection limit of 0.012 and 0.1 ng/ml in buffer and serum, respectively, which was 8-fold lower than that in RIA/FIA. In serum of HYPEX rats, LH was undetectable (< 0.04 ng/ml), whereas a high background level of 2.5 ng/ml was measured in the FIA. In serum of cycling rats, only a very low LH level of 0.14 ng/ml was measured, which strongly deviated from the level of 3.46 ng/ml with an FIA. The load of LH in serum of OVX rats was 2.91 ng/ml, which was 12-fold lower than that for the FIA. The peak level of LH was detected on proestrus Day 2 with RIA, FIA, and IFMA. In conclusion, two IFMAs for rFSH and one for rLH have been developed with high sensitivity and specificity for intact gonadotropins. The LH pattern during the estrous cycle was comparable between IFMA, RIA, and FIA, although the overall level in the IFMA was much lower, as were HYPEX levels. The FSH pattern differed only on proestrus Day 2 in the IFMA from that of RIA/FIA, showing a peak level with RIA/FIA and a basal level with the IFMA. This implies that in RIA/FIA measurements, proteins other than intact FSH and LH interfere with the analysis at proestrus Day 2 for FSH and in HYPEX, cycling, and OVX rats for LH.

1291 related Products with: Development of time-resolved immunofluorometric assays for rat follicle-stimulating hormone and luteinizing hormone and application on sera of cycling rats.

Rat follicle-stimulating Rat Thyroid Stimulating H GLP 1 ELISA Kit, Rat Gluc Follicle Stimulating Horm Mouse Anti-Human Follicle Mouse Anti-Follicle Stimu Rabbit Anti-Follicle Stim Luteinizing Hormone Relea MOUSE ANTI HUMAN LUTEINIZ Rat adrencocorticotropic Rat growth hormone releas Glucagon ELISA KIT, Rat G

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#2768439   1989/09/27 Save this To Up

Quantitative determination of staphylococcal enterotoxin A by an enzyme-linked immunosorbent assay using a combination of polyclonal and monoclonal antibodies and biotin-streptavidin interaction.

A sandwich enzyme-linked immunosorbent assay to detect staphylococcal enterotoxin A (SEA) was developed by using monoclonal antibodies (MAb) to SEA as primary capture antibodies. The antigen was detected with purified rabbit anti-SEA antibody as the secondary antibody. The secondary antibody was identified by direct conjugation with biotin or via biotinylated sheep F(ab')2 fragments to rabbit antibody. The biotin was then reacted with avidin-alkaline phosphatase (AP) conjugate, avidin-biotin-AP conjugated complex, or streptavidin-AP conjugate. The enzyme was identified by using p-nitrophenylphosphate. The incorporation of the avidin-biotin-AP conjugated complex or streptavidin-AP conjugate augmented the sensitivity 32-fold over that of the enzyme-linked immunosorbent assay without these reagents. Controls were run by substitution of the anti-SEA MAb with unrelated MAb of the same isotype. Sample values were considered positive when the A405 exceeded those of the negative controls by 3 standard deviations (greater than 99% confidence interval). The toxin could be quantitated with purified SEA standards through linear regression analysis with lower detection limits of 4 ng/ml (r = 0.99) and 0.25 ng/ml (r greater than or equal to 0.98). Concentrations of protein A up to 10 micrograms/ml did not cause interference. Analyses of crude growth extracts of SEA-secreting strains of Staphylococcus aureus were reproducible and were expressed in terms of 95% confidence intervals. Lack of cross-reactivity was seen with extracts of other toxigenic and nontoxigenic strains of S. aureus. The assay can be completed in one working day, provided that MAb-coated plates are available.

1472 related Products with: Quantitative determination of staphylococcal enterotoxin A by an enzyme-linked immunosorbent assay using a combination of polyclonal and monoclonal antibodies and biotin-streptavidin interaction.

Biotin antibody, Monoclon Androgen Receptor (Phosph Androgen Receptor (Phosph EIA for Quantitative Dete EIA for Quantitative Dete Androgen Receptor (Ab 650 Rabbit Anti-Streptavidin Rabbit Anti-Human Androge Goat Anti-Human Androgen Rabbit Anti-Rat Androgen Leptin ELISA Kit, Human A Rat monoclonal anti mouse

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