Gram staining is a lab test performed frequently to analyze and discriminate among the two types of bacteria that are gram-negative ones and gram-positive ones on the basis of the color held by them after the test.
Q. Among these two types of bacteria, which one is more harmful?
A positive bacterium has a thick outer wall as compared to the negative one. However, it is weak and permeable to foreign particles to invade them while gram-negatives although having a thin layer are very strong and almost impenetrable by any foreign particles. So, it can be a bit difficult for drugs to kill them as compared to the positive ones making them more powerful and harmful.
Peptidoglycan is a substance found in the outermost walls of bacterial cells. Those bacteria which have a thick layer of it are known as Gram-positive and those with a very slender layer of it occupying their superficial layers are labeled as Gram-negative. On carrying out this test on them, the positive ones get a purple or blue color because of the thick layer and the negative ones get a red or pink color.