428 SUMMAKY OF CURRENT RESEARCHES RELATING TO 



Preservation of Living Red Blood-cells in Vitro.* — P. Rous and 

 J. R. Turner point out the practical value of the preservation of red 

 cells for use in serum reactions, culture media, and even for transfusion. 

 One-eighth p.c. gelatin is added to the solution in which the cells are 

 washed, the use of this reagent protecting the cells from mechanical 

 injury. Though gelatin acts as a protective for red cells it is not a 

 preservative of them in any real sense. Cells do not last longer when 

 it is added to the fluid in which they are kept. Lock's solution, though 

 better probably than Ringer's solution, or a sodium chloride solution, 

 as a medium in which to keep red cells is ultimately harmful. The 

 addition of innocuous colloids does not improve it. But the sugars, 

 especially dextrose and saccharose, have a remarkable power of prevent- 

 ing its injurious action, and they possess, in addition, preservative 

 quaHties. Cells washed in gelatin (Lock's) and placed in a mixture of 

 Lock's solution with an isotonic watery solution of a sugar remain 

 intact a long time — nearly two months in the case of sheep's cells. The 

 kept cells go easily into suspension free of clumps ; they pass readily 

 through filter-papers, take up and give off oxygen, and when used for 

 the Wassermann reaction behave exactly as do fresh cells of the same 

 individual. The best preservation solutions are approximately isotonic 

 with the blood serum. If the cells are to be much handled, gelatin 

 should be nresent, for the sugars do not protect against mechanic.d 

 injury. 



Different preservative mixtures are requked for the cells of different 

 species. Dog cells last longest in fluids containing dextrine as well as 

 a susrar. The mixture best for red cells is not necessarily best for 

 leucocytes. 



A simple and practical method of keeping rabbit and human 

 erythrocytes is in citrated whole blood, to which sugar solution is 

 added. In citrated blood as such, human red cells tend to break down 

 rather rapidly, no matter what the proportion of citrate, haemolysis 

 being well marked in a little more than a week. But in a mixture of 

 three parts of human blood, two parts of isotonic citrate solution (3 • 8 p.c. 

 sodium citrate in water), and live parts of isotonic dextrose solution 

 (5 • 4 p.c. dextrose in water) the cells remain intact for about four weeks. 

 Rabbit red cells can be kept for more than three weeks in citrated blood, 

 and the addition of sugar only lengthens the preservation by a little. 

 The result differs strikingly with the amount of citrate employed. 

 Hemolysis occurs relatively when the smallest quantity is used that 

 will prevent clotting. The optimim mixture has three parts of rabbit 

 blood to two of isotonic citrate solution. 



Anaerobes Isolated from Wounds-f — Muriel Robertson, working 

 with material derived from gangrenous wounds sent her from Flanders 

 by Major Rowland and others, has succeeded in isolating therefrom 

 BaciUus perfringens {B. wrogenes capsulatus, "Welch and Xuttall : 

 B. WeJchii, avicii. ; B.phhgmones emphybematosse, Fraenkel), 5. cedematis 

 maligni (Koch), and a bacillus closely related with Hibler's bacillus 

 No. 9, and also allied to Rodella's bacillus Xo. 3. 



* Journ. Exper. Med., xsiii. (1916) pp. 219-37. 

 t Journ. Path, and Bact., xx. (1916) pp. 327-49. 



