galactopyranoside or crp b d galactopyranoside is specific for the total coliform group of bacteria the aforesaid test mixture with a nutrient indicator one skilled in the art would select such as onp b d galactopyranoside or crp b d galactopyranoside or others is specific for the total coliform group of bacteria and with a second nutrient indicator one skilled in the art would chose such as mug or others would be specific for the simultaneous detection of e coli the aforesaid test mixture is an example of an acceptable test mixture and aspects of the present test mixture are not limited to these examples as indicated above the micro particles are understood to increase the surface area in the sample test mixture admixture and allow microbes that multiply in vitro to establish a biofilm the micro particles provide multiple attachment surfaces for the microbes to u201c establish residence u201d microbes prefer surfaces to grow and multiply on a surface rather than while being free in a liquid environment the microbes experience quorum sensing which accelerates the generation of a biofilm the biofilm is produced when the microbes multiply and it yields colonies of microbes that are held together by external capsules of the microbes which in the broad context.