A MULTIPLE-PIPETTE HOLDER FOR THE DISTRIBUTION 

 OF SERUM FOR THE COMPLEMENT-FIXATION TEST 



By Francois H. Reynolds 



Pathological Division, Bureau of Animal Industry, United States Department of 



Agriculture 



DISADVANTAGES OF FORMER METHOD 



Those engaged in the performance of complement-fixation tests, 

 especially in laboratories where such work is conducted on a large scale, 

 readily can appreciate the necessity for the so-called "short-cuts" con- 

 sistent, of course, with accuracy, and one's imagination can readily appre- 

 ciate the tediousness of removing the serums for diagnosis from about 

 I, GOO (daily average) and at times as many as 2,400 specimens. The 

 transferring of the serums from the bottles to the test tubes has been long 

 a matter of concern and required the employment of many assistants, 

 and even then it would consume the greater part, if not all, of the forenoon 

 in the distribution of the large number of samples. 



It might be stated here that the desired quantities of serum are placed 

 in test tubes containing 1.5 cc. of physiological salt solution and in- 

 activated for half an hour at 58° C, the other ingredients being added 

 thereto later. 



The pipettes employed in the measuring of the necessary amounts of 

 serum were those of the i-cc. variety, made of glass, and graduated into 

 tenths and hundredths. Such pipettes are filled by suction with the 

 mouth and controlled by the index finger, and although one may become 

 quite expert in the handling of the same, the constant reading of the 

 smaller graduations is not conducive to good vision. Such pipettes are 

 not infrequently of a larger diameter than the opening in the serum bottle, 

 their use in such cases requiring the uptilting of the bottle with conse- 

 quent agitation of its contents, a feature not at all desirable ; and, further, 

 the utilization of this method of serum measurement meant the con- 

 suming of several hours and the assistance of numerous operators. 



Necessity therefore prompted the creation of a device which has over- 

 come all the objectionable features above enumerated and has made pos- 

 sible the transferring of serums from bottles to test tubes a matter of 

 comparative ease, requiring but a short space of time and demanding but 

 few operators, all of which are especially desirable in this era of time and 

 labor saving. 



After deliberation it was concluded that the new device now utilized 

 and illustrated herein would satisfactorily meet the existing conditions 



Journal of Agricultural Research, \'ol. XV, No. ii 



Washington, D. C. Dec. i6, 1918 



qp Key No. A-4S 



(615) 



88095°— 19 4 



