These sequences differ between prokaryotic and eukaryotic transcripts. Eukaryotic mRNA also contains sequence information important for efficient ribosome binding. The consensus sequence, termed a Kozak sequence, is ACC AUG G where AUG is the initiation codon. The presence of a consensus ribosome binding site or Kozak sequence is important when trying to optimize protein expression both in vivo and in vitro. Prokaryotic in vitro expression systems include the E. coli S30 Extract Systems.
Absorbance is directly proportional to the number of living cells in culture in most systems.
During the assay, MTS is converted into a soluble formazan product that does not require the addition of an organic solubilization solution. The CellTiter 96 Assays have also been used for bacteria, fungi and protozoa. The MTS-based CellTiter 96 AQ ueous One Solution System is the most convenient method for routine 96 well assays. For situations where extremely low background absorbance is critical or when assay plates must be stored for extended periods prior to recording data, the MTT-based CellTiter 96 System is the method of choice. The E. coli mut S gene is involved in mismatch DNA repair.