why will old gram-positive cells stain gram-negative?

Answer 1

Gram positive cells stain gram positive because of teichoic acid that binds the peptidoglycan layers of the cell walls together. Gram positive cells have 25 to 30 layers of peptidoglycan in their walls, whereas gram negative cells only have one or two layers. As the cells age their walls start to break down and cannot retain the stain. They lose layers of their peptioglycan or the teichoic acid isn't as effective. I hope that helps.

Answer 2

Gram Positive Cells

Answer 3

because the integrity of the capsule is not maintained. Well that's just my guess.