Orius sc600a camera

The hydrodynamic diameter, obtained by dynamic light scattering (DLS), and the zeta potential of the QDs were measured with a Malvern 4700 system (Malvern instruments Limited, UK) at 15 nM in water, RPMI-1640 medium with and without 1% or 10% horse serum, and DMEM with or without 2%, 10%, and 15% fetal bovine serum at 37°C. Data are presented as the average of 30 readings (10 readings per replicate).
The QDs were prepared for transmission electron microscopy (TEM) by placing a drop of suspended QDs onto a copper grid coated with a holey carbon support film (Agar Scientific Ltd) and plunge frozen in liquid ethane followed by freeze drying preserving the original features of the QDs (Hondow et al., 2012 ). Images were subsequently captured. Images were collected by an FEI Tecnai TF20 FEG-TEM operating at 200 kV fitted with a Gatan Orius SC600A camera and an Oxford Instruments INCA 350 energy dispersive x-ray (EDX) system with an 80 mm² X-Max SDD detector.

Exposed cells were centrifuged to collect a cell pellet which was fixed with 2.5% phosphate buffered (pH 7.3) glutaraldehyde (2h) prior to post-fixation in 1% Millonig’s buffered (pH 7.3) osmium tetroxide (120min). Samples were then dehydrated through an ethanol series (10min each, 10%, 70%, 100%), then transferred to 100% propylene oxide and resin embedded. Ultrathin-sections (70nm) were then cut for each cell pellet using a Leica EM-UC7 microtome and Diatome Ultra 45° diamond knife. Grids were carbon coated and images captured using a FEI Tecnai TF20 FEG-TEM operating at 200kV coupled with a Gatan Orius SC600A camera and an Oxford Instruments INCA 350 EDX system with an 80mm² X-Max SDD detector. For each cell treatment assessed, >10 cell sections were analysed.