Exhibit 99.1 MaxCyte Reports First Quarter 2024 Financial Results and Updates 2024 Guidance ROCKVILLE, MD, May 7, 2024 — MaxCyte, Inc., (NASDAQ: MXCT; LSE: MXCT), a leading, cell- engineering focused company providing enabling platform technologies to advance the discovery, development, and commercialization of next-generation cell therapeutics and innovative bioprocessing applications, today announced its first quarter ended March 31, 2024 financial results and updated its 2024 guidance. First Quarter High ...