Dried blood spot preparation
LYSED, ALDRICH
For every serological suspect two types of DBS were prepared. On a Whatman grade 4 filter paper, 16 drops of 30 µl of heparinized blood were deposited and left to dry. In parallel, 180 µl of heparinized blood were lysed for 5 min with 20 µl of 5% SDS solution (Sigma Aldrich, Saint Louis, MO, USA), and 2 drops of 40 µl of lysed blood were deposited on a Whatman grade 1001 filter paper. Filter papers were dried, packed in separate envelopes, which in turn were packed in hermetic plastic bags containing silica gel.