Carl libra 120

The sample grids were prepared as previously described^{17 (link)}. TEM images were obtained using a CARL ZEISS Libra 120 (Carl Zeiss AG, Oberkochen, Germany) or a HITACHI-7100 (Hitachi, Ltd, Tokyo, Japan) transmission electron microscope, in both cases running at 100 kV, coupled with a Gatan Ultrascan 1000 CCD (2000 × 2000 pixels) camera (GATAN, Pleasanton, California, USA) to record the images.

Hemocyte suspensions from each fraction were fixed in 2.5% glutaraldehyde prepared in ASW for 1 h. Subsequently, samples were washed three times in ASW solution, embedded in 1% agarose, post-fixed in 1% osmium tetroxide for 1 h in the dark at 4 °C, washed three times again, contrasted in 1% uranyl acetate for 1 h at room temperature (RT), washed again, dehydrated using a graded series of ethanol (10 to 96%) and acetone, then embedded in mixture of Epon 812, Araldite M and DDSA (at a 1.67:1:3.67 ratio, respectively). Semi-thin sections (0.75 μm) were prepared using a HM-360 rotary microtome (MICROM International GmbH, Germany) and stained with methylene blue, then analyzed using Zeiss Primo Star microscope. Ultrathin sections (65 nm) were prepared using a Reichert Ultracut S microtome (Leica, Germany) and mounted on a copper grid using butvar film, then additionally contrasted with lead citrate. Samples were observed with a Carl Zeiss LIBRA 120 transmission electron microscope (TEM) (Carl Zeiss, Germany).