2010 tem microscope

For TEM, 1% by weight peptide solutions in TFE or Milli-Q H₂O were diluted to concentrations ranging from 0.1 to 0.01% by weight with Milli-Q water. All samples were prepared via negative staining on Quantifoil R1.2/1.3 holey carbon films on copper mesh grids. Each peptide was spotted and allowed to adsorb for 1 min before excess peptide was blotted. A 2 wt % phosphotungstic acid (PTA) solution in Milli-Q water was prepared at pH 7 and sterile filtered. The sample grids were negative stained for 5 min in PTA. Excess PTA was wicked off the grids before the samples were dried and imaged at 120 kV and 40K magnification using a JEOL 2010 TEM microscope (JEOL USA Inc., Peabody, MA).

Peptide solutions of 0.05 % by weight in Milli-Q water were diluted from a 1% by weight stock solution, 10 mg/mL of peptide in 149 mM sucrose and 0.5X HBSS for K₂ and R₂. Same conditions were used for the stock solution of E₂ and D₂ with the addition of 22.5 mM MgCl₂. The peptide solution was spotted on Quantifoil R1.2/1.3 holey carbon films on copper mesh grids and allowed to absorb for 1 min before the excess was blotted. Negative staining was performed using 2% by weight phosphotungstic acid (PTA) solution in Milli-Q water at pH 7. The samples were negatively stained for 5 min in PTA, and then the excess solution was removed. Samples were air dried and imaged at 120 kV and 40K magnification using a JEOL 2010 TEM microscope (JEOL USA Inc., Peabody, MA).

Peptide nanostructure was studied by TEM. All samples were prepared via negative staining on Quantifoil R1.2/1.3 holey carbon films on copper mesh grids. Peptide samples were prepared at concentrations ranging from0.1 to 0.01 wt %, and 10 μL from each solution was spotted onto individual grids. Excess peptide solution was blotted after being allowed to adsorb for 1 min. The sample grids were negative stained for 5 min using a 2 wt % phosphotungstic acid (PTA) solution in MQ H₂O prepared at pH 7 and sterile-filtered. Excess PTA solution was wicked of the grids before drying overnight. Prepared samples were imaged at 120 kV and 40 000× magnification using a JEOL 2010 TEM microscope (JEOL USA Inc., Peabody, MA).