PAPER CHROMATOGRAPHY 381 



A list of the amino acids that were positively identified is as follows: 

 cystine, aspartic acid, glutamic acid, serine, glycine, asparagine, thre- 

 onine, alanine, gliitamine, a-amino-n-butyric acid, histidine, arginine, 

 lysine, methionine sulfoxide, proline, valine, methionine, isoleucine, 

 phenylalanine, tryptophan, and tyrosine. The potato tissue was 

 extracted with cold 70 to 80 per cent alcohol to give a protein-free solu- 

 tion. The alcohol extracts were evaporated to dryness under reduced 

 pressure and redissolved in water to give a solution containing about 



ALANINE 



PHOSPHOENOLPYRUVATE 



PHOSPHOGLYCOLATE 

 PHOSPHOGLYCERATE 



DIHYOROXYACETONE PHOSPHATE ^ 





RIBULOSE PHOSPHATE ^ 



RIBOSE PHOSPHATE 

 FRUCTOSE PHOSPHATE 8 MANNOSE PHOSPHATE 

 GLUCOSE PHOSPHATE 8 SEOOHEPTULOSE PHOSPHAT 



> 



NUCLEOTIDES 



60 SEC. PS CHLOBELLA 



RIBULOSE DIPHOSPHATE 8 HEXOSE DIPHOSPHATE 



/ 



Fie;. 8-7. Autoradiograni of two-dimensional chromatogram showing incorporation of 

 radioactivity in various substances by Chlorella during 60 sec of photosynthesis while 

 exposed to C*. {From M. Calvin and J. A. Bassham, Studies in Photosynthesis ivith 

 Isotopes, University of California Radiation Laboratory Report UCRL-1861, 1952.) 



10 mg/ml of nitrogen. Five microliters of the solution was applied to the 

 filter paper and developed chromatographically for about 30 hr in phenol 

 saturated with water. After drying, the paper was turned at right angles 

 for another 30-hr development in a coUidine-lutidine mixture. Dent (43) 

 studied in detail the chromatographic behavior of some 60 amino acids 

 and ninhydrin-reacting substances. 



Steward et al. (44) w-ere able to gain additional information on the 

 occurrence of sulfur-containing amino acids by chromatography and auto- 

 radiography of extracts of alfalfa into which S^^ had been introduced via 

 the roots. Thompson et al. (45) investigated the variables affecting the 

 chromatographic separation of plant amino acids and the ninhydrin reac- 



