1.1 ,This test method covers an immunological method to determine the amount of protein in Guayule Natural Rubber (GNR) and its products using rabbit antisera specific for Guayule Natural Rubber latex proteins. This immunoassay procedure quantitatively measures the level of GNR proteins in solution using an inhibition format. The samples may include but are not restricted to, gloves or other GNR product extracts, and liquid GNR samples which have been collected in order to measure the protein levels.