Optimized fixation of actin filaments for improved indirect immunofluorescence staining of rickettsiae

Monika Danchenko (1) , Lucia Csaderova , Pierre Edouard Fournier (2, 3) , Zuzana Sekeyová (1)

1 SAS - Slovak Academy of Sciences
2 VITROME - Vecteurs - Infections tropicales et méditerranéennes
3 IHU Marseille - Institut Hospitalier Universitaire Méditerranée Infection

Objective The objective was to investigate fixative solutions: 3.7% formaldehyde, 4% paraformaldehyde, 4% paraformaldehyde in the cytoskeletal buffer and 4% paraformaldehyde in PHEM buffer (containing PIPES, HEPES, EGTA and MgCl2), applicable for immunofluorescence assay. Results Herein we optimized this serological technique, testing four fixative solutions, for the sensitive detection of rickettsial antigens, and preservation of intracellular structures of the host cells, particularly filamentous actin. Rickettsial antigens were presented equally well both with formaldehyde and all paraformaldehyde-based fixations, but only protocol with 4% paraformaldehyde in PHEM buffer allowed accurate imaging of actin filaments, and simultaneously allows monitoring of rickettsiae using actin-based motility during infection inside the host cells.

Mots clés: Immunofluorescence assay; Rickettsiae; Cytoskeleton fixation; Cell culture; Actin-based motility

Domaines: Bactériologie; Cardiologie et système cardiovasculaire; Maladies émergentes; Maladies infectieuses; Parasitologie; Virologie

Monika Danchenko, Lucia Csaderova, Pierre Edouard Fournier, Zuzana Sekeyová. Optimized fixation of actin filaments for improved indirect immunofluorescence staining of rickettsiae. BMC Research Notes, 2019, 12 (1), ⟨10.1186/s13104-019-4699-9⟩. ⟨hal-02469781⟩