18 MATERIALS AND PROCESSES OF SLIDE-MAKING 



Note: Make up the stain -by first dissolving the hematoxylin in the acid and 

 alcohol. Then dissolve 1 Gm. of ammonium alum in the water and add this 

 together with the glycerin. Shake well and add about 10 Gm. of ammonium 

 alum to the bottle. Allow to ripen some months, making sure that there are 

 always a few crystals of ammonium alum in the bottom of the bottle. This 

 stain keeps well for about 10 years and works best after it is a year old. Large 

 laboratories, therefore, should make up half a gallon every two or three years 

 in order to have well-ripened material always in stock. 



STAIN IS USED AS FOLLOWS: 



1. Accumulate the sections in 90 per cent alcohol. 



2. Place each slide for Vi to 2 minutes in the staining solution. 



3. Remove each slide and drop 90 per cent alcohol on it either from a 

 drop bottle or a pipette until the excess stain has been removed. 



4. Transfer the slides directly to alkaline tap water until blue. 



Note: If the sections are taken directly from water to stain or from stain to 

 water, a diffuse stain which is very difficult to differentiate will result. 



Indirect Nuclear Hematoxylin Stains 



These stains are better employed for wholemounts than for sections. They 

 always give a more or less diffuse result, which is excellent for showing up 

 various organs in a wholemount of a small invertebrate or of an embryo. 

 They are excellent, however, for staining botanical sections in which the xylem 

 becomes sharply and clearly stained a bright blue. 

 Carazzi's Alum Hematoxylin ("Hemalum"): 

 Staining solution 



Water 80 ml. 



Potassium alum 5 Gm. 



Hematoxylin 0.1 Gm. 



Potassium iodate 0.02 Gm. 

 Glycerin 20 ml. • 



Differentiating solution 



0.1% hydrochloric acid in 70% alcohol 



Note: First the hematoxylin should be dissolved in the solution of potassium 



