Lindberg herbs and extracts undergo rigorous quality control measures to ensure you get high quality herbs! We conduct scientific tests to meet our high standards. Lindberg Herbs are scrutinized with various scientific tests to ensure they live up to our high standards. These tests may include microbiological, enzyme-linked immunosorbent assay, high-performance liquid chromatography, thin-layer and gas chromatography, purity and ash testing, moisture determination and more.