Alexander Greer is an organic chemistry professor with 25 years of experience in photochemistry, singlet oxygen, peroxy intermediates, and photodynamic therapy. He is also an associate editor of Photochemistry & Photobiology, former president of the American Society for Photobiology, co-chair of the Committee of Concerned Scientists, and a co-founder of SingletO2 Therapeutics LLC that is involved in bacterial biofilm eradication.