A small portion
(ca. 1 mg) of the lyophilized solid was suspended in a 50% (v/v) ethanol/water
mixture. Negative staining was done by adapting standard procedures36 as follows. A 5 μL drop of the sample
suspension was placed on a 300-mesh nickel-covered carbon film TEM
grid (FCF300-Ni Formvar Carbon Film) from Electron Microscopy Sciences
(Hatfield, PA), allowed to evaporate for 30 s, and then blotted with
filter paper. A 5 μL drop of 1% uranyl acetate dye was then
placed on the grid and blotted immediately. A JEOL 2100 TEM instrument
(JEOL Ltd., Tokyo, Japan) was used with a LaB6 beam source,
a beam strength of 200 kV, and a current density of 30–60 pA/cm3. Images were captured with an Ultrascan 1000 camera (Gatan
Inc., Pleasanton, CA) and processed to derive lamellar spacings with
Digital Micrograph software (ver. 2.11.14.04.0, Gatan Inc.). At least
eight spacing measurements were made at different locations for each
of the self-assemblies and plant phellem tissues, allowing us to determine
mean values and standard errors for each value.
(ca. 1 mg) of the lyophilized solid was suspended in a 50% (v/v) ethanol/water
mixture. Negative staining was done by adapting standard procedures36 as follows. A 5 μL drop of the sample
suspension was placed on a 300-mesh nickel-covered carbon film TEM
grid (FCF300-Ni Formvar Carbon Film) from Electron Microscopy Sciences
(Hatfield, PA), allowed to evaporate for 30 s, and then blotted with
filter paper. A 5 μL drop of 1% uranyl acetate dye was then
placed on the grid and blotted immediately. A JEOL 2100 TEM instrument
(JEOL Ltd., Tokyo, Japan) was used with a LaB6 beam source,
a beam strength of 200 kV, and a current density of 30–60 pA/cm3. Images were captured with an Ultrascan 1000 camera (Gatan
Inc., Pleasanton, CA) and processed to derive lamellar spacings with
Digital Micrograph software (ver. 2.11.14.04.0, Gatan Inc.). At least
eight spacing measurements were made at different locations for each
of the self-assemblies and plant phellem tissues, allowing us to determine
mean values and standard errors for each value.