Results of polymerase chain reaction showing 230-bp and 161-bp bands for Balamuthia (lanes 1–6) and Acanthamoeba (lanes 7–12) mitochondrial 16S rRNA gene DNA. Lane 1, molecular mass marker; lane 2, absence of Balamuthia DNA in patient brain tissue (5-μL sample); lane 3, positive control (Balamuthia DNA); lane 4, negative control (Acanthamoeba DNA); lane 5, negative control (water); lane 6, absence of Balamuthia DNA in patient brain tissue (1-μL sample); lane 7, molecular mass marker; lane 8, Aca