Healthy human biofluids were spiked with the Zika virus PRVABC59 strain from infected Vero cell supernatants at a final concentration of 106 PFU/ml. (A) Amplification of 2 μl of serial 10-fold dilutions of plasma containing 106 PFU/ml of the PRVABC59 strain followed by dilution to 1:100 or 1:1000 in water. (B) Matching samples of the 1:1000 plasma dilutions were incubated in tubes in a heat block for 70 min and examined for turbidity. (C) Tenfold dilutions of blood, saliva, urine, and semen each spiked with 106 PFU/ml of PRVABC59 Zika virus strain followed by dilution to 1:1000 in water. Virus input: (A and C) 2000 PFU (black circles), 200 PFU (black triangles), 20 PFU (black squares), 2 PFU (black diamonds), 0.2 PFU (black crosses; below threshold), 0.02 PFU (no symbols; gray line below threshold), infected Vero cell RNA (positive control; red circles), and diluted biofluids without virus (no symbols; black line below threshold). Results are representative of a minimum of six replicates of each dilution series. X axis, minutes to LAMP amplicon incorporation of fluorescent dye; y axis, RFUs.