Parasites were labeled with polyclonal rabbit antibodies to MSP1-19 and secondary antibodies (anti-rabbit Alexa594 to detect MSP1-19 labeling

and anti-mouse Alexa488 to detect internalized MSP2 MAbs, with anti-MSP1-19 at a 1:200 dilution and secondary antibodies at a 1:500 dilution).

Internalized MSP2 MAbs were detected up to 19 h postinvasion. Images are from representative antibodies to the C-terminally conserved region. The labeling of internalized MSP2 MAb was colocalized

with labeling of MSP1-19 by polyclonal rabbit antibodies, further suggesting that MAbs to MSP2 were bound to the parasite surface postinvasion. Lower panel: 3D7 strain merozoites were fixed during invasion for EM and labeled with MSP2 N-terminal antibodies. A repre-sentative image of a merozoite prior to and during invasion is shown. Labeling is indicated with red arrows.

Boyle MJ, Langer C, Chan JA, Hodder AN, Coppel RL, Anders RF, Beeson JG. Sequential processing of merozoite surface proteins during and after erythrocyte invasion by Plasmodium falciparum. Infect Immun. 2014 82(3):924-36.