

SERUM MEDIA 77 



The serum inspissator is practically an incubator with 

 slightly inclined (10-15 degrees) shelves, on which the tubes 

 rest, and thus the serum is coagulated in a sloping position. 



Fluid serum, etc. Fluid blood-serum, ascitic and 

 hydrocele fluids, etc., are sometimes useful, and may be 

 used alone or mixed with peptone beef -broth in various 

 proportions. 



Ascitic or hydrocele fluid may be obtained by using 

 sterile trocars, etc., and carrying out the tapping with 

 aseptic precautions, collecting the fluid in sterilised flasks. 

 It is better to collect in several small flasks than in one 

 large one. 



Fluid blood-serum may be obtained by collecting blood 

 with aseptic precautions in sterilised flasks. When the 

 blood has coagulated and the serum separated, the serum 

 is pipetted off with a sterile pipette into sterile flasks. 



The flasks of serum, etc., should be kept in a warm 

 place for two or three days to make sure that they are 

 sterile, those in which a growth appears being rejected. 



Serum, ascitic fluid, etc., may also be obtained sterile 

 by filtering through a sterilised Berkefeld filter into sterile 

 flasks. 



Serum, ascitic and hydrocele fluids, etc., may be pre- 

 served in bulk and used as required. The material is 

 collected as aseptically as possible, 0-5 per cent, of chlo- 

 roform is added, and the whole is well mixed. The 

 mixture is then placed in a well- stoppered bottle and 

 heated for an hour in a water-bath at 45 C., with occa- 

 sional shaking. It may then be stored. For use pipette 

 off 50 c.c. of the serum aseptically and place in a 

 sterile 200 c.c. bottle. Heat rapidly to 55 C. arid shake 

 thoroughly, or, better, place under the receiver of an 

 air-pump, partially exhaust, and shake. This procedure 

 removes the chloroform. 1 



1 For exact details see Fildes, Lancet, 1917, vol. i, p. 492. 



