Negative Result For Endospore Stain. By giving up a proton as an acid the chromophoreof the dye becomes negatively charged. Endospore negative cells stain red with no evidence of green staining.
Bacillus subtilis and clostridium are examples of endospore positive bacteria. Positive results indicate that the cell has the ability to form spores while negative results indicate that the cell does not produce spores why is it not necessary to include a negative control for the endospore stain procedure. As the endospores are resistant to staining the endospores are equally resistant to de-staining and will retain the primary dye while the vegetative cells will lose the stain.
The main purpose of endospore staining is to differentiate bacterial spores from other vegetative cells and to differentiate spore formers from non-spore formers.
In 1922 Dorner published a method for staining endosporesShaeffer and Fulton modified Dorners method in 1933 to make the process faster The endospore stain is a differential stain which selectively stains bacterial endospores. As a result of poorextreme environmental conditions vegetative cells undergo a process referred to as sporulation to form endospores. The name endospore is suggestive of a spore or seed-like form endo means within but it is not a true spore ie not an offspringIt is a stripped-down dormant form to which the bacterium can reduce itself. In Negative staining Preparations the Bacterial cells observed as the Clear transparent bodies or objects may be of variable size and shape if you are using a mixture of bacteria against a dark background.