European journal of applied microbiology and biotechnology

, Volume 5, Issue 2, pp 123–127

Rapid method for distinction of gram-negative from gram-positive bacteria

  • T. Gregersen
Industrial Microbiology

DOI: 10.1007/BF00498806

Cite this article as:
Gregersen, T. European J. Appl. Microbiol. Biotechnol. (1978) 5: 123. doi:10.1007/BF00498806


A rapid method for distinction between gram-negative and grampositive bacteria by means of a 3% solution of potassium hydroxide is tested on 71 gram-positive and 55 gram-negative bacterial strains. The method proved reliable with one exception only, a Bacillus macerans strain. That strain was definately gram-negative on staining. Other Bacillus strains were proved gram-positive by the test, even those being gram-negative on staining.

Copyright information

© Springer-Verlag 1978

Authors and Affiliations

  • T. Gregersen
    • 1
  1. 1.Veterinary Faculty for F.A.O. FellowsThe Royal Veterinary and Agricultural UniversityCopenhagen V.Denmark