Abstract
Experimental studies were performed to evaluate the application of separation by polyct iylene glycol (PEG) to the immunoassay of plasma glucagon.
An increase in the concentration of PEG added raised the percentage of precipitated bound 131I-glucagon, reaching a plateau at a 12.5 % final concentration of PEG. The bound labeled glucagon was completely precipitated by the addition of r-globulin of human plasma in a final concentration of 0.15 mg/ml. The maximal percentage of bound labeled glucagon precipitated was observed at pHs 7 to 9. The standard curve for glucagon assay using PEG was parallel to that using the charcoal method. The glucagon levels in the pancreatic vein of a dog measured by the PEG method correlated with those by the charcoal method (r=0.832).
These results suggest that the PEG method for the separation of free from bound labeled glucagon is useful and superior to other methods for the radioimmunoassay of plasma glucagon.
