Radiation Dose in Autoradiography 



135 



when the organism is killed at the time the specimen is 

 removed. 



d=!^^ tE, 



reps 



(39) 



If we assume an exposure time of 40 days we can deduce 

 the simple rule that autoradiographs using ^^C can be made 



MINIMUM DOSE TO TISSUE FOR A.R.G. 

 (TRACER REMAINS IN ORGANISM) 



f(r)=CONST jI-Io'e^ e^^ 



10,000 



lOOO 



REPS 



100 



IQ 



lO 



DAYS 



Fig. 6. 



15 



20 



2S 



with a radiation dose of 1 rep per day to the organism. The 

 same figure can, without undue error, be used for work with 

 ^^S. If X-ray film is used autoradiographs can be produced 

 with a radiation dose not exceeding the tolerance dose under 

 favourable conditions. 



These calculations assume that fine grained stripping film 

 is used for making the autoradiographs. For X-ray film the 



