0.6 



-0.4 



0.2 



CHlOROPHYll a IN ETHER 



T 1 — I — r 



1 — r 



A 



Integrated 



Derivative 



Curve 



// 

 II 



II 



II 



Measured 

 Absorbance 



I I 1 ^1-- 



650 



700 



^ 



o 

 o 



650 



700 



CHlOREllA ON AGAR 



0.6 



0.4 



0.2 



1 



J I L 



1 



J L 



o 

 o 



1— I 1 r 



■' \ 



650 700 



WAVEIENGTH.X 



650 



W A V E I E N G T H , A. 



700 



Fig. 11. Top, the red absorption band of chlorophyll a in ether, as 

 measured with the recording Beckman spectrophotometer (dotted line). 

 The first derivative of the absorbance of t^e same sample with respect to 

 wavelength plotted by the derivative spectrophotometer. The integral of 

 this curve (solid line) is compared with the directly measured absorbance 

 curve on the left. Bottom, the same type of data for live Chlorella cells 

 showing chlorophyll b more clearly in the derivative curve. The shoulder 

 of the derivative curve at 675-680 ni/-. indicates that this peak consists of 

 two components. 



32 



