High Throughput Processing of DNA Samples on FTA Paper for PCR Analysis

Abstract

from degradation nucleic acids from blood, plant and animal tissue extracts and other sources. For analysis, a small disc is punched from the FTA paper containing the DNA sample of interest, washed, dried and used for polymerase chain reaction (PCR). We wished to take advantage of the simplicity and speed of DNA isolation on the FTA paper and ease of storage that does not require freezing. For DNA isolation from plants, leaves are crushed on the FTA paper and the extract is allowed to soak into the paper and dry (1). Lacking, however, was an expedient and reliable procedure for processing moderate numbers of samples (up to several hundred) for analysis. One of the bottlenecks in the workflow is the FTA paper disc washing. For high throughput applications in diagnostic labs, fully robotized stations handle disc punching, washing and PCR. On the other end of the spectrum, a small number of discs can be placed in microcentrifuge tubes and the washing liquid added and removed manually using a pipettor (1). An improved method of disc washing was described by Lange et al. (2) who used a 96-well PCR plate modified by piercing a small hole in the bottom of each well. The holes were small enough so that 50 µl of the washing liquid was retained in the well by surface tension, yet large enough for the liquid to be pulled through and removed by centrifugation. Following washing and