Lea makes use of structural information from cryogenic electron microscopy and x-ray crystallography to understand biomolecules and medical pathways. She is particularly interested in molecular complexes that can cross the cellular membrane. She studies the serum resident protein cascades that are involved in immune responses. Lea has studied the interactions that define bacterial meningitis and dysentery. She determined the molecular architecture of the flagellum.[citation needed]
^E Blanc; P Roversi; C Vonrhein; C Flensburg; S M Lea; G Bricogne (December 2004). "Refinement of severely incomplete structures with maximum likelihood in BUSTER-TNT". Acta Crystallographica Section D: Biological Crystallography. 60 (Pt 12 Pt 1): 2210–21. doi:10.1107/S0907444904016427. ISSN0907-4449. PMID15572774. WikidataQ27860590.