Carotenoids are tetraterpenoid pigments occurring in chloroplasts of plants, in algae, bacteria and fungi. They absorb blue light energy for use in photosynthesis and protect from photodamage. In humans, some have vitamin A activity and/or antioxidant activity. A diet rich in carotenoids from natural food is good for health and protect from chronic illnesses. We provide main of our carotenoid reference materials titrated by UV spectroscopy as analytical standards for quantitative testing. Our carotenoid standards are used in many applications like food supplement and pigment, also in basic research as markers of plant metabolism.