Tip-enhanced laser ablation and capture of DNA

Abstract

Tip-enhanced laser ablation was used to extract DNA plasmid for polymerase chain reaction (PCR) amplification. A 532 nm nanosecond laser was directed onto a gold coated atomic force microscopy (AFM) tip 10 nm above a sample surface to ablate a 7.1 kbp green fluorescent protein (GFP) plasmid DNA sample on a glass coverslip. The ablated material was captured on a metal ribbon 300 µm above the sample surface. The ablation craters had diameters from 1 to 2 µm and an average volume of 0.14 µm3. PCR and nested PCR were employed for the amplification of the ablated DNA. The quantity of sample from each ablation crater for PCR amplification was 20 ag.