Time-lapse documentation of S. scabiei embryogenesis

Time-lapse microscopy was performed in two independent experiments. Two independent batches of 20 freshly laid eggs each (n = 40) were analysed. Twenty individual eggs were loaded into a microwell device at a time. Phase contrast images were captured using a 20× objective lens (N.A. 0.40) on the EVOSTM FL Auto 2 inverted microscope (Invitrogen, Thermo Fischer Scientific Corporation, USA) equipped with a motorized X-Y-Z stage. The microscope was housed in a commercial incubator (HeraCell VIOS 160i, Thermo Fisher) with capability to actively maintain embryos at 37 oC temperature, 5% CO2, 20% O2 with 85-90% humidity. Time-lapse images of 40 eggs were analyzed to identify the embryonic stages and morphological events in the S. scabiei eggs. Identified embryonic stages and morphological events were recorded in relation to time.