at 15,000 rpm for 5 min. The supernatant was removed from each tube and the pellet was allowed to air dry at room temperature for at least 2 h. During the first year sampling, dried pellets were resuspended in 1 ml TE (10 mM Tris HCl (pH 8.0)/1 mM EDTA). More recently we have reduced this volume to 500 ul to avoid low DNA concentrations.
