GOLD 249 



Where large amounts of fat were present, acetone or dioxane was used to 

 give a one-phase system suitable for licjuid counting (Au-3). In studies 

 with mice about 0.1 mc of a labeled solution was injected after the animal 

 had been inoculated and had grown sarcoma 37 cells. About O.Oo ml of 

 peritoneal fluid was withdrawn with a capillary glass pipette, diluted with 

 5 per cent sodium oxalate, and centrifuged to separate cellular content 

 from serous exudate. Each fraction was dried in a tin cup and counted 

 with a mica-end-window tube (Au-4). A method has been described for 

 electrodeposition of gold from biological tissues (Au-5). The weighed 

 tissues are digested with aqua regia or concentrated HNO3 plus Superoxol, 

 and 5 mg gold as the chloride is added. After digestion the HNO3 is 

 replaced by HCl, and the solution evaporated to 1 or 2 ml. This is 

 treated with NH.OH-HCl and 0.4 per cent FeS04-7H20 to reduce the 

 gold, which is then centrifuged. The precipitated gold is dissolved in 

 aqua regia, is made alkaline with NaOH, and is ready for electrodeposi- 

 tion. Good recoveries of radiogold from biological tissue have been 

 reported by a procedure based on treatment of an acid hydrolyzate with 

 activated carbon (Au-6). 



Au-1. Natelson, Samuel, and Joseph L. Zvickerman: Estimation of Gold in Biological 

 Materials, Anal. Chem., 23: 65:^-655 (1951). 



Au-2. Stapleton, J. E., and W. J. Wingo: Intracavity and Interstitial Administration 

 Methods for Radioactive Colloidal Gold, Nucleonics, 11: 60-62 (1953). 



Au-3. Zilversmit, D. B., George A. Boyd, and Marshall Brucer: The Effect of Particle 

 Size on Blood Clearance and Tissue Distribution of Radioactive Gold Colloids, 

 J. Lab. Clin. Med, 40: 255-260 (1952). 



Au-4. Goldie, Horace, Lincoln B. Calvin, Homer Nash, and Paul V. Hahn: Radio- 

 active Colloidal Gold in Macrophages and Serous Exudate in Peritoneal Fluid 

 of Sarcoma Bearing Mouse, Proc. Soc. Exptl. Biol. Med., 76: 480-484 (1951). 



Au-5. Dunn, Rayburn: Recovery and P^stimation of Radioactive Isotopes from 

 Biologic Tissues, J. Lab. Clin. Med., 33: 1169-1176 (1948). 



Au-6. Weiss, Louis C, Arthur W. Steers, and Howard M. Bollinger: Determination 

 of Radioactive Gold in Biological Tissue, Anal. Chem., 26: 586-587 (1954). 



