Tem 1230 electron microscope

Dissected adult thoraces were fixed in modified Trump's fixative (0.1 M sodium cacodylate buffer, 1% glutaraldehyde, and 4% formaldehyde) at room temperature (22°C) for 30 min, and then at 4°C overnight. The fixed specimens were rinsed three times in 0.1 M sodium cacodylate buffer for 10 min, post-fixed with 2% osmium tetroxide in 0.1 M sodium cacodylate buffer for 30 min, rinsed three times in 0.1 M sodium cacodylate buffer for 10 min, and finally rinsed five times in ddH₂O for 10 min. The specimens were then stained en bloc with 2% aqueous uranyl acetate for 20 min, dehydrated in a graded ethanol series, and subsequently set into Spurr's embedding medium. Thin sections (90 nm) were stained with uranyl acetate and lead citrate, and imaged with a TEM1230 electron microscope (JEOL Company) and a 967 slow-scan, cooled CCD camera (Gatan). TEM images were processed with Photoshop CS4.

The average particle size of the MCs was determined using Dynamic Light Scattering (Malvern Instruments, Nano ZS90). The samples were diluted at ratios of 1:1000 with PBS prior to analysis. Cryogenic‐Transmission Electron Microscopy (Cryo‐TEM) was used to visualize the morphology of the MCs by using JEOL TEM‐1230 Electron Microscope, Peabody, MA, USA. To understand the difference in peptide density of each MC preparation, zeta potential was evaluated. The PEG‐b‐PPS/Pep‐PA MC and PEG‐b‐PPS MCs (termed blank MCs) were diluted in the ratio of 1:1000 with PBS. This solution was run in the (Malvern Instruments), Nano ZS90.