Note on a Simple and Rapid Method of Producing Romanowsky Staining in Malarial and other Blood Films

(From the Pathological Laboratory, Netley). SINCE the appearance of a note by me in the BRITISH MEDICAL JOURNAL of March i6th, I901, on Romanowsky staining, with special reference to its action on the parasite of malaria, I bave endeavoured still further to simplify the method by isolating the active staining ingredient of the compound dye and using it as a single stain. The results have exceeded my expectations, and the method which is described below gives not only the characteristic appearances of Romanowsky staining, but is so easy in its application, and necessitates so little time and skill in its manipulation that I venture to think it may with advantage be used for ordinary blood staining, in preference to many of the methods in general use. Beautiful results have also been obtained in the examination of " smear" preparations from bone marrow, from glands such as the spleen and liver and from cancer juice. 'The presence of bacteria in blood films and smear preparations is also demonstrated by this method with the greatest clearness and precision, while as a selective tissue stain for sections it appears to present many advantages. As a blood stain, from the point of view of time saving, it is also no small gain that in this method no separate process of fixation of the film is necessary, fixing and staining being performed at one and the same time by the staining fluid. The isolation of the active staining ingredient from the mixed solutions of methylene blue and eosin presented no great difficulty, but the selection of a suitable solvent and the practical application of the stain so as to simplify and shorten the teohnique was not so easy. It was found that the new dye when dissolved and applied to blood films only ,gave Romanowsky staining feebly and after being allowed to act for some hours, and it thus appeared to present little, advantage over the method previously described by me. But, after further experiment, it was found that the simple addition of distilled water in a particular manner produced 'brilliant Romanowsky staiaing in from two to five minutes according to the thinness and evenness of the blood Elm. The method which I will now describe as briefly as pos.sible has been used by myself and others in this laboratory for the last five months, and the results have proved ex'tremely regular and satisfactory. I have also recently reeeived a good report of its efficacy in the staining of malaria