Eriochrome black T Indicator is a complexing agent for metal ions (e g Ca2 Mg2 ) and is used as an indicator in complexometric titrations Eriochrome black T Indicator forms colored complexes with metal ions through covalent coordination bonds and indicates the endpoint of the titration by color change Eriochrome black T Indicator can be used as an anionic azo dye in photocatalytic degradation studies to evaluate the performance of photocatalysts The reaction solution of Eriochrome black T Indicator combined with Mg2 is initially purple During loop-mediated isothermal amplification (LAMP) the color changes from purple to sky blue due to the consumption of Mg2 by the formation of magnesium pyrophosphate indicating a positive reaction The optimal concentration of Eriochrome black T Indicator in LAMP is 60 M and the detection limit for Mycobacterium tuberculosis is 1 pg DNA/reaction[1][2]