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can acid fast test came out purple? please help - (Jul/22/2014 )

I did yesterday my second unknown test in micro lab and my Acid-fast test came out purple (both A and B), is it acid fast positive or non acid fast? I'm not sure how to interpret this,  the book says if it is blue is negative acid fast, if it is red positive. My is more like purple. Please help 

Gram stain came fro unknown A- positive for B- negative


The steps I did - apply carbofuschsin, wash with water, decolorize-alcohol, wash with water, counterstain with methylen blue, wash water



I had my second unknown test and A- came out gram positive (purple) and B - negative(pink). The problem I have is Acid fast interpretation. I followed exactly steps as I shuld carbofuchsin-water-alcohol-water-methylene blue. Both of my cultures appear purple under the microscope. What does it means?

The book says if it is red - acid fast, if blue - non acid fast.


Please help me to interpret.




Ok... these are obviously homework so I have moved it to the appropriate subforum. Bob.


If you tell us what you think is the reason, then people might be more willing to answer...


I do not understand what you mean GLobal moderator. I had an unknown test which included gram stain, acid fast, endospore staining , also citrate, catalyst, methyl red, nitric test, starch test and carbohydrate fermentation. I inoculated all the plates, tubes approprietly and did gram stain, acid fast stain and endospore stain. Then I looked under the microscope and tried to interpret stain techniques. 

The gram stain cam out purple for culture A and pink for culture B

Endospore came positive for culture A and negative for culture B


WHAT I'M NOT SURE IS how to decide for acid fast, because both cultures appera to me purple. The book says if RED=acid fast, if blue= non acid fast. SO then I should lean toward blue if I interpret well both are non acid fast. Correct me if I'm wrong please . This is my second unknown test and I'm making sure. Tommorow I will interpret rest of the tests.

thank you


Global moderator is the group that I belong to - like you are an active member -user name is above the image...


Anyhow... what I was meaning is what is your interpretation of the result?  Could you have done the test incorrectly (destained enough? for instance)?  Could it be that the sample is an ambiguous one, in light of other tests?


Analytical thinking is what you should be learning... we are (usually) happy to help if you have a problem, but you need to demonstrate that you are putting some thought in yourself, especially for these homework/test questions.