<prompt> Method used for acid fast staining -Robertsons methodZiehl NeelsenSilver imprignation methodDark ground illumination  <response>: Ans. is b i.e., Ziehl Neelsen Acid fast stainingo After staining with aniline dye, acid fast organisms resist decolourisation with acids,o Method most commonly used is modified Ziehl Neelsen.Smear stained by carbolfuschinDecolourization by 20 sulphuric acidCounterstaining by methylene blueAcid fast organismsNon acid fast organismsRetain fiischin red colourTake colour of methylene blue blue colourAcid fastness depends uponMycolic acid Integrity of cell wall 