Human growth hormone (hGH) (Somatropin) Pharmacokinetic ELISA

This assay employs the indirect sandwich enzyme immunoassay technique. Anti-GH is coated onto a 96 well microplate. Calibrator and test samples prepared by dilution into assay buffer and are pipetted into the appropriate wells. GH present in biological matrices is bound by the immobilized anti- GH antibody. After washing away any unbound substances, tagged antiGH secondary antibody is added to the wells. After washing, diluted detection reagent is added to the wells. The plate is washed to remove any unbound antibody-enzyme reagent and a substrate solution is added to the wells for color development. The color development is proportional to the amount of GH present in test samples. The color development is stopped and the intensity of the color is measured.

Coated microtiter plate, 96 wells (1x8 strips) 1 Calibrator diluent 1.8ml Calibrator (1mg/ml) 12μl 20X wash buffer 25ml Assay buffer 50ml 1000X secondary antibody 1000X detection reagent 17μl TMB 12ml TMB stop solution 12ml

Prepare only the appropriate amount of required reagent on the day of use. Store all reagents as per instructions stated on the label. 1. Wash Buffer (1X) Preparation: Dilute wash buffer concentrate with ultra-pure water 1/20 before use (for example add 25mL concentrate to 475mL ultrapure water) . Mix well. 2. Secondary Antibody (1X) Preparation: Dilute secondary antibody with assay buffer 1/1000 before use (for example add 12μl to 12mL of assay buffer) . Mix well. 3. Detection Reagent (1X) Preparation: Dilute detection reagent with assay buffer 1/1000 before use (for example add 12μl concentrate to 12ml of assay buffer) . Mix well. 4. Calibrator Preparation: Dilute the calibrator from 1mg/ml down to 5µg/ml by pipetting 5µL of calibrator stock into 995µL assay buffer. Label "Cal. Int." Mix well. Prepare calibrators with concentrations ranging from 500 ng/ml to 9.375 ng/ml. The following is an example calibrator curve.

This assay employs the indirect sandwich enzyme immunoassay technique. Anti-GH is coated onto a 96 well microplate. Calibrator and test samples prepared by dilution into assay buffer and are pipetted into the appropriate wells. GH present in biological matrices is bound by the immobilized anti- GH antibody. After washing away any unbound substances, tagged antiGH secondary antibody is added to the wells. After washing, diluted detection reagent is added to the wells. The plate is washed to remove any unbound antibody-enzyme reagent and a substrate solution is added to the wells for color development. The color development is proportional to the amount of GH present in test samples. The color development is stopped and the intensity of the color is measured.

1. Construct a standard curve by plotting the absorbance obtained from each standard against concentration. Use a 4 or 5 parameter curve fit. 2. The concentration of the unknowns can be back calculated directly from this standard curve using the absorbance value for each sample. 3. Any sample diluted more or less than the standard series will need additional data correction. For example, if the sample is diluted 1/50, then the concentration will be calculated by dividing by 2 due to the calibrators being 2 times more diluted. Similarly, if the sample is diluted 1/500, then the concentration will be calculated by multiplying by a correction factor of 5 due to the calibrators being 5 times more concentrated.

Dilute calibrators and test samples 1/50 with assay buffer (for example add 5µL of prepared calibrator or sample to 245µL of assay buffer) . Mix well. Do not store diluted samples.