DS 23.211 



DYE STAINS OF SPECIAL APPLICATION 



473 



scope, to be very deep blue, while the 

 general background of the section is pink. 

 After a little practice the required color 

 may be gaged without examination under 

 the microscope. 



These specimens are not permanent 

 unless the alcohol and resin are removed 

 from tliem. It is desirable, therefore, as 

 soon as differentiation is complete, to 

 dehydrate them in absolute alcohol and 

 then clear them in at least three changes of 

 xylene, so as to make sure that no alcohol 

 can be carried over into the mounting 

 medium. 



23.21 BACTERIA IN SMEARS 



Bacterial smears are rarely, if ever, 

 fixed. Hence, they share with blood smears 

 the ability to be stained by a method 

 depending not only upon the chemical 

 composition of the material, but also upon 

 the isoelectric point of the protein from 

 which it is produced. Smears may be 

 prepared either upon the slide or the 

 coversUp, and are usually from cultures 

 which have been heavily diluted either 

 with the medium upon which they are 

 grown or with an isotonic salt solution. 



S3.S11 General Methods 



It would be quite impossible to gather in one place all the stains which have, from time to 

 time, been recommended for use with bacterial smears. Such a listing of techniques would 

 have to include every stain recommended for staining nuclei, and the great majority of syn- 

 thetic stains when adjusted to a suitable pH. Gathered here are only those solutions which 

 are commonly found in laboratories of bacteriology, or those which involve some departure 

 from the normally recognized techniques, such as the early stain of Claudius 1897, or its more 

 recent modification by Spehl 1927. It must be emphasized again that the staining of a particle 

 by any of the methods given is no voucher for the bacterial nature of the particle. Many of 

 the techniques given are almost indistinguishable from the techniques recommended for the 

 display of mitochondria, therefore, some other evidence than staining is required to prove 

 the existence of bacteria. 



23.211 Claudius 1897 857, 11 :332 



REAGENTS REQUIRED: A. DS 12.15 gentian violet; B. sat. aq. sol. picric acid 50, water 



50; C. chloroform 

 method: [dry smears] — > A, flooded on slide, 2 mins. -^ quick rinse — > B, 1 min. — > blot 



and let dry — > C, till no further color removed — ♦ balsam 



23.211 Conn 1928 20540b, 26:257 



formula: water 100, phenol 5, calcium chloride 0.01, rose bengal 1 

 method: [smears of gelatin-suspended soil dried at 100°C.] — » stain, on slide, heated on 

 water, bath, 1 min. — > water, wash — > dry 



23.211 Ehrlich 1882 7276:270 



formula: abs. ale. 10, gentian violet 5, sat. sol. aniline 90 

 preparation: Add the aniline to a solution of the dye in ale. 

 method: As Ziehl 1882 see also DS 23.213 Koch 1884 



23.211 Goodpasture test. 1938 Mallory Mallory 1938, 274 



formula: water 70, 96% ale. 30, aniline 1, phenol 1, magenta 0.6 



23.211 Hucker test. 1929 Conn McClung 1929, 93 



formula: 95% ale. 20, crystal violet 2, water 80, ammonium oxalate 0.8 

 preparation: Add the oxalate dissolved in water to the dye dissolved in ale. 

 method: As Ziehl 1882 

 note: a detailed description of the use of this technique is given under DS 23.20 above. 



23.211 Loffler 1890 for formula see DS 11.44 Loffler 1890; for method see DS 23.211 Ziehl 



1882 



23.211 Maneval 1941 20540b, 16:13 



formula: water 95, phenol 3.9, acetic acid 5, ferric chloride; 3, either acid fu<'lisin 0.01 or 



anilin blue 0.05 or fast green FCF 0.05 or light green 0.05 

 method: [air-dried or heat-fixed smear] — > stain, 1 min. -^ wash — > dry 



