Protein quantitation using dyes obtained from plant materials

We present a preliminary report on the use of plant dyes in the quantitation of proteins in solution. We have used ethanol, acid, alkali and water to extract dyes from some plant materials, including flowers of Jungle flame (Izora coccinea), China rose (Hibiscus rosa-sinensis) and leaves of West African Indigo (Lonchocarpus cyanescens), Mimosa (Mimosa pudica), Roselle (Hibiscus sabdarifa), Jatropha (Jatropha curcas) and Henna (Lawsonia inermis). The dyes obtained were used in the protein-dye binding studies. The colour of the protein-dye complex of the ethanolic extracts was stable and increased linearly with increase in protein concentration. The extracts achieved linearity up to the following amount of proteins in the test samples: Hibiscus rosa-sinensis (60 mg), Ixora coccinea (120 mg), Hibiscus sabdarifa (80 - 100 mg), Jatropha curcas (80 mg), and Lawsonia inermis (100 mg). The sensitivity of the dyes especially at low protein concentrations indicate that they can provide suitable alternatives to other well known standard methods of protein determination.