1947-5764/18/$35.00 © 2018 by Begell House, Inc. www.begellhouse.com 121 Plasma Medicine, 8(2):121–129 (2018) G uid e line s fo r Using 3- Nitro - L- Tyro sine a s a n A ntid e g ra d a tio n Re a g e nt o f H 2 O 2 in the C o ld A tm o sp he ric Pla sm a - Stim ula te d So lutio ns Dayun Yan, a,* Niki Nourmohammadi, b Julian Milberg, c Jonathan H. Sherman, d & Michael Keidar a,* a Department of Mechanical and Aerospace Engineering, The George Washington University, Sci- ence and Engineering Hall, 800 22 nd Street, NW, Room 3550, Washington, DC 20052, USA; b De- partment of Epidemiology, Columbia University, Mailman School of Public Health, 722 West 168 th Street, New York, NY 10032, USA; c Department of Biomedical Engineering, University of Miami, 1251 Memorial Drive McArthur Engineering Building, Coral Gables, FL, 33146-0621, USA; d Neu- rological Surgery, The George Washington University, Foggy Bottom South Pavilion, 22 nd Street NW, 7 th Floor, Washington, DC 20037, USA *Address all correspondence to: Dr. Dayun Yan, Department of Mechanical and Aerospace Engineering, The George Washington University, Science and Engineering Hall, 800 22nd Street, NW, Room 3550, Washington, DC 20052, USA; Tel.: 202-994-6929, E-mail: ydy2012@gwmail.gwu.edu; or Dr. Michael Keidar, Department of Mechanical and Aerospace Engineering, The George Washington University, Science and Engineering Hall, 800 22nd Street, NW, Room 3550, Washington, DC 20052, USA; Tel.: 202-994-6929, E-mail: keidar@gwu.edu ABSTRACT: Over the past decade, cold atmospheric plasma (CAP)-stimulated solutions (PSS) have shown promise in medicine and agriculture. The degradation of important CAP-originated reactive species, particularly H2O2 in PSS during storage, weakens the application potential of PSS. In this study, the guidelines for the use of 3-nitro-L-tyrosine as an antidegradation reagent of H2O2 in PSS have been proposed through preliminary investigations. KEY WORDS: cold plasma, 3-nitro-L-tyrosine, antidegradation I. INTRO DUC TIO N Cold atmospheric plasma (CAP) is a near–room-temperature ionized gas composed of electrons, positive charged ions, and neutral particles. 1 Dozens of reactive species are generated in the gas phase of CAP, including hydroxyl radicals, singlet oxygen, super- oxide, ozone, and nitric oxide. 2 CAP has shown a promising application in medicine through its selective anticancer capacity on dozens of cancer cell lines 3,4 and also in agriculture through protecting the food and seeds from the threat of pathogen as well as improving the germination of seeds. 5,6 Recently, the CAP-simulated biologically adapt- able solutions (PSS) such as medium and simple bu൵ered solutions have also been dem- onstrated to be an e൵ective selective anticancer tool. 7–9 Particularly for the in vivo application, PSS can be directly injected into the tumor- ous tissues in the mouse, which cannot be assessed directly by CAP. 10,11 In agriculture, PSS can also be used to inactivate the yeasts on grapes 5 and to improve the seeds’ germi- nation rate. 6 The stable storage of PSS over a relatively long time (e.g., 1 week) is nec-