CYTODIAGNOSIS AND SPINAL FLUID EXAMINATIONS 427 



Test. Put 1 1 clean dry test-tubes in a rack and deposit in the first tube 1.8 c.c. 

 of a 0.4% solution of sterile saline. Into the other 10 tubes put only i c.c. of the 

 0.4% saline. Into the first tube deliver 0.2 c.c. of spinal fluid and mixing 

 thoroughly we have 2 c.c. of a i-io dilution. Withdraw i c.c. from the first tube 

 and add to the i c.c. of saline in the second tube. This gives 2 c.c. of 1-20. 

 Continue the process until the No. i to No. 10 tubes contain i c.c. quantities of the 

 various dilutions from i-io to 1-5120. 



Tube ii contains no spinal fluid but only i c.c. of the saline and serves as a 

 control. 



To each of these n tubes add 5 c.c. of the colloidal gold reagent. The color 

 changes are usually read after the tubes have stood over night at room tem- 

 perature. The proper color of the control in tube n should be salmon red or old 

 rose and the fluid should be perfectly transparent. When the color is changed in 

 tubes containing dilutions of the spinal fluid we record one showing a bluish tint 

 as i. When the change is to a lilac we record it as 2. A distinct blue is marked 

 as 3 and a pale blue as 4. When decolorization is complete there is the highest 

 color change, which is noted as 5. 



All glass-ware used in the test should be thoroughly washed in soap and hot water 

 and then carefully rinsed with tap water. Next use the bichromate-sulphuric acid 

 cleansing fluid, followed by most thorough washing in running water followed by 

 distilled water. 



In preparing the reagent a 2 liter glass beaker, following the above-described 

 cleansing, is rinsed in double or triple distilled water, made with block tin condens- 

 ing tubes and without rubber connections. Then fill the beaker with triple dis- 

 tilled water up to a ^ liter mark. Heat the water gradually to 6oC. Now 

 add 5 c.c. of a i% aqueous solution of Merck's yellow crystalline gold chloride 

 and 3^ c.c. of a 2% aqueous solution of desiccated potassium carbonate. Con- 

 tinue the heating of the solution, which should remain clear, to 8oC., then 

 add 5 drops of a i% aqueous solution of oxalic acid, stirring all the time. The solu- 

 tion should be colorless after adding the oxalic acid. When the temperature reaches 

 QOC. remove the flame and add drop by drop 5 c.c. of i% formalin solution, 

 stirring continuously. Should a pink color show itself before all the formalin solu- 

 tion has been added stop the further addition. It soon assumes the required shade 

 and when cool should be perfectly transparent and of an old rose or orange-red color. 



Globulin Increase Tests. The test generally used is Noguchi's buty- 

 ric acid one. Deliver into a small test-tube 0.5 c.c. of a 10% solution 

 of butyric acid in 0.9% salt solution. Then add o.i c.c. of spinal fluid. 

 Bring to a boil over a flame and add o.i c.c. of N/i NaOH solution. 

 If there is a considerable increase of globulin a flocculent precipitate 

 appears in a few minutes or at any rate in one or two hours. Fluids 

 with a normal content or only slight increase only show a slight opacity. 



The odor of the butyric acid is very objectionable and in our laboratory we use 

 the Ross-Jones method. In this one deposits in a small tube about i c.c. of satu- 

 rated solution of ammonium sulphate. On the surface of this column we deposit 

 i c.c. of spinal fluid. If globulin increase is present a turbid ring appears within 



