Following a PhD in Protein Biochemistry from Aberdeen University, she joined M-Scan Ltd. in 1984 to found the Biochemical Services Department. Here she pioneered and applied developments in Mass Spectometry for structural characterisation. She was appointed Director of Biochemical Services in 1988. At the same time she was instrumental in establishing a facility in the United States where she was appointed Vice President. Dr. Greer was responsible for establishing the Quality Management Systems and for directing Quality Assurance across the four M-Scan laboratories. With over 30 years of experience in the structural analysis of glycoproteins using instrumental techniques she has published many articles on the use of mass spectrometry to fulfil regulatory characterisation requirements. She is regularly invited to give presentations at international meetings and has designed and presented various training cources. She is now Global Director for Biopharma Services Development, SGS M-Scan.