Brown MX-5BR or Reactive Brown 10 has a formula of CHClCrNNaOS and a molecular weight of 1163.6 g/mol, containing two dichlorotriazine rings.  Brown MX-5BR, for example, can be used to purify lysozyme, phosphinothricin acetyltransferase. It also shown that it can elute tryptophanyl-tRNA synthetase using Trp as eluant, however, tryptophanyl-tRNA and tyrosyl-tRNA synthetase are the only t-RNA that can be elute out using Brown MX-5BR.