GRAM STAINING
Who could have guessed that a staining procedure devised more than a century ago would still serve as one of the most widespread methods of bacterial classification? Microbiologists of this high-tech age are still indebted to Danish physician Christian Gram, who invented the gram-staining method in 1884.
The differences in the cell wall are more than simply a classification tool. Cell wall characteristics are intimately related to the disease-causing potential of the bacterium. In fact, medical researchers have found that an extremely effective way to combat bacterial pathogens is by interfering with cell wall formation. Because the eukaryotic cell has no analog to the prokaryotic cell wall, medicines which target bacterial cell walls have little or no effect on plant or animal cells.