~40,000,000 molecules/rod cell
||Arnadóttir J, Chalfie M. Eukaryotic mechanosensitive channels. Annu Rev Biophys. 2010 39: doi: 10.1146/annurev.biophys.37.032807.125836. 111-37. p.112 right column top paragraphPubMed ID20192782
||Nathans J. 1992. Rhodopsin: structure, function, and genetics. Biochemistry 31: 4923–31PubMed ID1599916
||"Each mammalian rod has approximately
4?10^7 molecules of rhodopsin (primary source) and each moth olfactory cell has been estimated to have approximately 1.7?10^7 odor receptors (ref 106)."