FLLORESCEXCE MICROSCOPY 



cence after treatment with greatly diluted 

 fluorchrome solutions in contrast to staining 

 with vital stains, which are effective only at 

 relatively high concentrations. Hence it is 

 possible to fluorchrome any organ in full 

 function without damaging it. 



In addition to basic research, fluorescence 

 microscopy is being employed more and more 

 for routine chnical diagnostic purposes in 

 the following : 

 hematology 



for leucocyte counts, for differentiating 

 leucocytes, and for counting thrombo- 

 cytes; 

 bacteriology 



for streak cultures, differentiation of 

 acid-resistant bacilli (t.b. and leprosy) 

 from nonacid-resistant bacilli, for the 

 demonstration of spirochaetes; 

 parasitology 



for the demonstration of trypanosomes 

 and other flagellates, plasmodia, and 

 other sporozoa. 

 By means of fluorchroming it is also pos- 

 sible to demonstrate the elementary bodies 

 of the so-called large virus types. For this 

 purpose even small outfits are suitable, 

 equipped solely for fluo-violet (BV) excita- 

 tion, since all these fluorchromed objects 

 have their fluorescence in the long-wave 

 region. 



For characterizing the fluorescent sub- 

 stances one uses the spectral distribution of 

 the fluorescent phenomena. This is done by 

 means of a pupillary spectroscope attached 

 to the tube of the microscope, using the UV 

 filter combination as excitation filter. Since 

 the spectroscope furnishes an average color 

 value of the observed field of view, an iris 

 diaphragm is mounted in the eyepiece of the 

 pupillary spectroscope for eliminating all 

 structures which do not fluoresce in the 

 same color. Above all, the pupillary spectro- 

 scope in connection with the various excita- 

 tion filter combinations permits adapting the 

 choice of barrier filters to the spectral emis- 



sion of the fluorescing substance and thus to 

 utilize fully the filter intermediate tube. 



Naturally the fluorescence outfit is also 

 adapted to the observation and evaluation 

 of virtually structureless fluorescent mate- 

 rial, i.e., for observing the fluorescence of 

 licjuids and (cell) suspensions. For this pur- 

 pose one places on the microscope stage a 

 small shallow cell which after filling is closed 

 with a cover glass. Preferably an objective 

 of low magnification is used. The fluorescence 

 spectrum can be observed through the 

 pupillary spectroscope. The great advantage 

 of this micro method of observing the fluo- 

 rescent spectrum is the possibility of carry- 

 ing out the examination of very small sam- 

 ples. (See also Fluorescence, Fluorophotometry 

 in the "Encyclopedia of Spectroscopy." 



REFERENCES 



Richards, O. W. : (Latest advances with extended 

 bibliography) Medical Physics, Vol. Ill, p. 

 375. Year Book Publ. Inc., Chicago, 111., 1960. 



Lehmann, H., "Lumineszenzanalyse mittels der 

 UV-Filterlampe." Verh. Dtsch. Physik. Ges. 

 13, 1101-1104 (1911). 



Reichert, K., "Das Fluoreszenzmikroskop," 

 Phys. Z., 12, 1010-1011 (1911). 



Lehmann, H., "Das Luminiszenz-Mikroskop, 

 seine Grundalgen und seine Anwendungen," 

 Z. wiss. Mikroskopie, 30, 417-470 (1913). 



Dhere, Ch., "Nachweis der biologisch wichtigen 

 Korper durch Fluoreszenz und Fluoreszenz- 

 spektren in: Abderhalden, "Handbuch der 

 biologischen Arbeitsmethodeu," Abt. II, Teil 

 3, Halfte 1, 3097-3306. Verlag Urban and 

 Schwarzenberg, Berlin-Vienne, 1934. 



Haitinger, M., "Die Methoden der Fliioreszenz- 

 mikroskopie," Ibid., 3307-3337. 



Haitinger, M., "Fluoreszensmikroskopie. Ihre 

 Anwendung in der Histologie und Chemie," 

 Akademische Verlagsgesellschaft, Leipzig, 

 1938; 



De Ment, J. "Fluorescent Chemicals and their 

 Application," New York, 1942. 



Meyer, H. and Seitz, E. C, "Ultraviolette 

 Strahlen. Ihre Erzeugung, Messung und An- 

 wendung in INIedizin, Biologic und Technik," 

 Verlag Walter de Gruyter and Co., Berlin, 

 1942. 



Fonda, G. R. and Seitz, F., "Preparation and 

 chai'acteristics of solid luminescent mate- 

 rials," John Wiley and Sons, New York, 1948. 



333 



