In this early work, however, the activating effects of the natural ligand, acetylcholine, were not measured and, also, atropine apparently only partially inhibited the receptor. In the current paper, therefore, we recloned this receptor (named A-type mAChR) and found that the cDNA sequence published in Shapiro et al.
At an early age we learn that the color of the water in our lakes, rivers and ponds is blue, but we expect the water in our drinking glass to be clear. When homeowners discover their home drinking water has a slight blue tint, itâs cause for concern. Blue or blue-green water likely means it contains copper.
The quinine in tonic water causes it to grow bright blue under a black light. Science Photo Library / Getty Images The bitter flavoring of tonic water is due to the presence of quinine, which glows blue-white when placed under a black light. You'll see the glow in both regular and diet tonic water.