FIG. 1.
Selection of filter paper. Filter disks of 3 mm in diameter (A to D) and a solution (Control) containing 5 × 105 (lane 1), 5 × 104 (lane 2), 5 × 103 (lane 3), and 0 (lane 4) genome copies of purified CMV (Towne strain) were added to reaction mixtures for the conventional PCR assay. Numbers of CMV genome copies were determined by the real-time PCR assay described previously (17). Filter papers compared were as follows: FTA Micro card (Whatman, United Kingdom) (A), Generation Capture card (Gentra Systems Inc., Minneapolis, MN) (B), plain filter for blood collection (Advantec, Japan) (C), and Isocode (Schleicher & Schuell, Germany) (D). After PCR amplification, the PCR products were analyzed by gel electrophoresis. Arrows indicate the expected PCR products. Lane M, 1-kb DNA ladder marker.