SUGGESTIONS TO TEACHERS OF BIOCHEMISTRY 



2. Methods of applying the biuret test 

 JOHN L. KANTOR and WILLIAM J. GIES 



(Laboratory of Biological Chemistry of Columbia University, at the College of 

 Physicians and Surgeons, New York) 



About three years ago the senior author was given the agreeable 

 duty of planning the equipment of the laboratory of physiological 

 chemistry in the nevv'ly erected Household Arts building at 

 Teachers College. When the time came to decide upon the capac- 

 ity, number and labeling of the reagent bottles to be purchased for 

 each laboratory desk, it was found that we could not provide all the 

 desired reagents (32), in uniform sets of Containers in the avail- 

 able shelf space, if bottles of greater capacity than 4 oz. were 

 selected for the purpose. We then proceeded to study the Situation 

 from its practical Standpoints, especially with regard to the use of, 

 and the need for, each of the intended reagents. 



From the esthetic point of view, the selection of 4 oz. bottles 

 left nothing to be desired. It seemed likely, however, that if such 

 small bottles were employed, some of them would be emptied so fre- 

 quently, and would have to be filled so often, that considerable loss 

 of time would be involved in their use. On the other band, that the 

 smallness of the supply of each particular reagent would encourage 

 economy and neatness in the use of all the reagents, was equally 

 probable. 



The only reagent which this study led us to fear would be 

 employed so freely as to cause embarrassment because of frequent 

 emptying and refilling of the bottles, was 10 per cent. sodium 

 hydroxid Solution (the preferred representative of the caustic 

 alkalies). The reasons for this fear were the frequency of the need 

 for this reagent by the Student, both for general purposes and in 

 applications of the biuret test. The usual tendency to excessive 

 alkalization of needlessly large portions of the liquids under exam- 



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