MEDICO-BIOLOGIC RESEARCH 



followed by washing in running water for 

 about half a day. 



Dehydration and embedding proceeds as 

 follows : 



4 changes of acetone of at4east 10 min- 

 utes each 

 10% bio-plastic in acetone for 24 hours 

 20% bio-plastic in acetone for 24 hours 

 30 % bio-plastic in acetone for 24 hours 

 3 changes of 100% bio-plastic for 24 

 hours each. 

 Mold releasing compound (Ward's) is ap- 

 plied to the inner surface of a dish which aids 

 in removing the block from the mold. When 

 dry, fresh bio-plastic is poured into the dish 

 and catalyst added (tertiary-butyl-hydro- 

 peroxide). The correct ratio between the 

 amounts of plastic and catalyst is important; 

 25 cc of plastic and 7 to 8 drops of catalyst 

 is used in this laboratory. 



After the specimen has been immersed in 

 the mixture it is allowed to polymerize at 

 room temperature for 48 hours. When 

 ready, the block is cut to approximately 2 

 cm^ size with a zig-zag saw and afterwards 

 sectioned with the Jung microtome (Fig. 

 24). The block surface is slightly moistened 

 with water and after cutting the section is 

 unrolled on a piece of plastic. The upper sur- 

 face of the section is blotted, turned around 

 with the aid of a probe and blotted again. 

 Afterwards the sections are stored between 

 two glass slides. Sections are usually strong 

 enough to stand this handling if care is ob- 

 served. After radiography the sections are 

 colored. Presently good results are achieved 

 with the following procedure : 



Stain 5 to 10 minutes in 10 cc of sat. sol. 

 Thionin (approx. 1 %) in 50 % alcohol and 

 90 cc of 1 % phenol in water (Nicolle 1871) 



wash in distilled water 



remove excess stain bathing for 5 seconds 

 in 25 cc of dist. water to which 1 drop of 

 HCl has been added 



wash well for few minutes 



counterstain for 10 minutes or longer in 

 }/'2 % eosin in water 



Fig. 24. .Jung bone microtome type K. (Heidel- 

 berg, W. GermanyJ. 



Technical Data: 



Knife 3H" xiH". 



Length of rails 40 cm 16 inches. 



Total vertical excursion. .30 mm l}i inches. 



Automatic adjustment 

 of the thickness of the 

 sections up to 50 microns. 



in steps of 2 microns. 



Maximum size of the ob- 

 jects to be clamped . . 80 by 55 mm 



Ground space of the mi- 

 crotome 80 bj' 40 cm 



Height of the instru- 

 ment 40 cm 



Weight 90 kg approx. 210 pds. 



wash in distilled water 



dip shortly in 70 % alcohol (in and out) 



differentiation is completed in absolute 

 alcohol till clouds of stain cease coming out 

 of the section 



clear in xylene and mount in premount 

 (Fisher Scientific). 



With this coloring the bone appears rosy 

 or red, soft tissues in different shades of blue. 



This coloring is now used together with 

 the previously reported Boehm-Oppel and 

 Schmorl methods. 



SUPPLE IVIENT 



New Data 



For the current and previous years several 

 contributions to micro-biological research 



621 



