Leo 1530 gemini scanning electron microscope

Heart perfusions were performed using PBS and subsequently 4% (w/v) PFA. Pieces of mouse intestine (approx. 3 mm edge lengths) were fixed with 2.5% (v/v) glutaraldehyde and 4% (w/v) PFA in 0.1 M sodium cacodylate buffer pH 7.2 for 2 h. The samples were washed three times with 0.1 M sodium cacodylate buffer and were then dehydrated with increasing ethanol concentrations (30, 50, 70, 80, 90 and 100% (v/v)).
Afterwards, samples were dried with a CPC 030 critical point dryer (BAL-TEC) using liquid CO₂ and coated with gold (2–3 nm coating thickness) by a SCD005 Sputter Coater (BAL-TEC).
Images were taken with a Leo 1530 Gemini scanning electron microscope (Carl Zeiss AG), recorded digitally with a secondary electron detector at 8 kV and processed by ImageJ and Adobe Photoshop software.

M. sexta proboscises were cut 1 cm from the tip and fixed in 4% glutaraldehyde at 4°C overnight. Proboscises were then dehydrated in an ascending ethanol series (70%, 80%, 90%, 96%, 3x 100% ethanol, 10 min each), critical point dried (BAL-TEC CPD 030, Bal-Tec Union Ltd., Liechtenstein), mounted on aluminium stubs with conductive carbon cement (Agar Scientific, UK) and sputter coated with gold on a BAL-TEC SCD005 (Bal-Tec, Liechtenstein). Specimens were examined in a LEO 1530 Gemini scanning electron microscope (Zeiss, Germany) set at 8 kV and 11 to 15 mm working distance.