Why is it important that crystal violet is a darker stain than safranin?

it's for bio, gram stain.. thx!!

Why is it important that crystal violet is a darker stain than safranin?
It allows for the differentiation between gram postive and gram negative bacteria.



You stain with the Crystal Violet, then you apply a mordant (iodine), then you rinse with alcohol or acetone and then you stain with the safranin.



If the bacteria is Gram Positive, the Crystal Violet will "stick" to the cell wall. If it is gram negative, the crystal violet will "wash off" and then the safranin will be visible.(pink)



The safranin also stains the gram positve but you cannot see it over the darker Crystal Violet.



This allows the differentiation to be Purple=postive, Pink=negative.