water and twice with distilled water and autoclaved with EDTA solution. 

 After autoclaving, the flasks were rinsed again with distilled water, 50 

 ml of Mi llipore-f iltered sea water was introduced into each flask and they 

 were again autoclaved at 15 p.s„i. for 15 minutes. When soil extract, M2M, 

 was added to the flasks, this was Mi llipore- f i Itered , autoclaved separately 

 and added aseptically to the flasks,, Six (6) flasks were used. In flasks 

 #1 and #2, 1 ml (approx. 10 p, c) Cs-137 solution was added to the 50 ml sea 

 water, in flasks #3 and ^M , 1 ml Cs-137 solution and 2.5 ml M2M soil extract 

 was added to the 50 ml sea water, and in flasks #5 and #6, 2 ml Cs-lS'? solution, 

 and 2.5 ml M2M soil extract was added to the 50 ml sea water,. Immediately, 

 and at 24-hour intervals ,20C;\aliquots of the solutions were removed from 

 the flasks, placeri'on stainless steel planchets and dried for counting. The 

 results shown in table 2 show that there was no loss of radioisotope from 

 the medium to the glassware during the 74-hour study. 



Table 2 



The Loss of Cs-137 from Medium to Glassware 



The accumulation and loss studies using the radionuclide, Cs-137 were 

 conducted in much the same manner as were the strontium studies except the 

 cells were washed free of the isotopes before filtration. The phytoplankton 

 cultures used in these experiments were again grown in an enriched sea water 

 medium under controlled light and temperature. 



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