Spectrum Chemical manufactures and distributes fine chemicals with quality you can count on including those with CAS number 298-93-1, Whether you call it MTT, 3-(4 -5-Dimethylthiazol-2-yl)-2 -5-diphenyl-2H-tetrazolium Bromide or Thiazolyl Blue you can be assured the MTT products offered by Spectrum, meet or exceed the grade requirements or specifications for each individual product.