I was fortunate to do my military service during the Vietnam era as a medical officer at the National Institutes of Health (NIH) in Bethesda. Maryland. My first research at NIH was concerned with making a variety of optical measurements on nucleic acid bases and proteins. including single crystal spectra in linearly polarized light and near infrared circular dichroism. https://www.marketingjeunesse.com/product-category/black-dye-shampoo/