Atomic force microscopy of uncoated plasmid DNA: nanometer resolution with only nanogram amounts of sample.
Reproducible, high-contrast, nanometer-resolution AFM images of uncoated plasmid DNA can be obtained with nanogram quantities of DNA with the help of two advances in sample preparation: (1) Heating a DNA solution at 35 degrees C for 10 to 20 minutes before deposition on mica helps separate and spread the DNA, and (2) Using 5 microliter drops of the heated DNA solution in the concentration range of 2 to 10 nanogram/microliter in contact with a specially prepared mica surface for 5 to 10 minutes gives optimal coverage with only nanograms of DNA.
Li
M Q
MQ
Department of Physics, University of California, Santa Barbara 93106.
Hansma
H G
HG
Vesenka
J
J
Kelderman
G
G
Hansma
P K
PK
D000538:Aluminum Silicates / Q000737:chemistry; D004247:DNA / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D010957:Plasmids / Q000737:chemistry*
D000538:Aluminum Silicates; D004247:DNA; C011934:mica