Determination of Beads A volume required for immunocapture of American Type Culture Collection (ATCC) strain 19698 of Mycobacterium avium subsp. paratuberculosis (MAP). For each Beads A volume used, DNA was run undiluted (N) and at dilutions of 1:10 (−1) and 1:100 (−2). The bead volumes were as follows: lanes 1 to 3, 10 μL; lanes 4 to 6, 20 μL; lanes 7 to 9, 30 μL; lanes 10 to 12, 40 μL. Lane −C — negative water control; lane M — 1-kb molecular weight marker; bp — base pairs.