Motor End Plates 211 



References: Culling (1957); Lillie (1954); Mettler (19!^2); Mettler and 

 Hanada (1942); Poirier et al. (1954); and Swank and Davenport (1934 

 A,B and 19S5 A,B). 



Motor End Plates 



Cole Method (1946) (Whole Mounts) 



fixation: none, carry fresh tissue directly into step 1. 



procedure: 



1. Remove striated costal muscle and place in 10% citric acid in 

 physiological saline (page 410): minimtim time 10 minutes, maxi- 

 mum 30 minutes. 



2. Transfer directly to 1% aqueous gold chloride (1 gm./lOO ml. 

 ^vater). Make up day before used. Keep in dark: 60 minutes or 

 until tissue turns dark yellow. (If pieces are larger than 4 mm. in 

 width a longer time is required.) 



3. Transfer directly to 20% aqueous formic acid (20 ml./80 ml. wa- 

 ter): 10-20 hours in dark. Do not use metal forceps, coat them 

 ^vith paraffin or use glass rods. 



4. Rinse in tap water. 



5. Transfer to 95% methyl alcohol-glycerol (1:1): several hours. 

 Then remove top of container and allow alcohol to evaporate. 



6. Transfer to pure glycerol. 



7. To mount: with a sharp razor cut muscle strips into small pieces. 

 Place a piece in a very small drop of glycerol (usually, amount 

 carried over by the piece is sufficient) on a round cover glass. Lay 

 a smaller size cover glass over it. Spread the muscle fiber to single 

 fiber thickness by using gentle pressure and strokes at right angles 

 to the fibers. Turn cover glasses over and mount in Permount (or 

 the like) on a glass slide. (Double cover glass mounting, page 123.) 



results: 



muscle fibers — red-blue 



motor end plates and medullated axons — black 



muscle fiber nticlei — unstained 



Carey's {1941) modification: 



Carey used undiluted fresh filtered lemon juice in place of the 

 citric acid. He claimed that if longer than 12 hours was required in 

 the formic acid (step 3), the gold chloride technic was faulty. The 

 color of the tissue should be gold, not brown. 



