Fig 2. Color change of neutral red and phenol red indicator dyes in LAMP reactions.

The WbLDR primer set was used to amplify genomic W. bancrofti (Wb) DNA using the colorimetric master mix containing either neutral red or phenol red dye and Bst 2.0 WS. Before amplification (T₀), reactions containing neutral red are colorless. Samples turn pink if positive or a brownish yellow if negative as shown after a sixty minute (T₆₀) amplification. Reactions containing phenol red are pink at T₀ and remain pink if negative but turn yellow if positive as shown here after a sixty minute (T₆₀) amplification.