Are there any circumstances where Gram positive bacteria stain red and not purple?

2 Comments

1. Mr. Biostud says:

   October 29, 2009 at 7:26 am

   Erees13, theoretically it should not be.

   Remember that the principle employed in tests like this is the reaction to the dye. The reaction will determine the classification or the nature of the bacteria. However, such thing could be possible if the staining procedure was wrong. Otherwise it’s impossible.

   Hope this helps..
2. Nayru says:

   October 29, 2009 at 7:26 am

   Gram positive bacteria are supposed to stain purple. If they stain red (after both stains are supplied), it usually means that they are gram negative.