ic8      Chemical  Reactions  of  Diphtheria  Antitoxin.  {  Am.  jour.  Pharm. 
April,  1917. 
SOME  EXPERIMENTS  ON  THE  CHEMICAL  REACTIONS 
OF  DIPHTHERIA  ANTITOXIN. 
By  Albert  C.  Crawford  and  Carlton  L.  Andrus.1 
Many  of  us  expect  to  find  that  future  advances  in  rational  thera- 
peutics will  be  made  along  chemotherapeutic  lines  and  by  following 
the  methods  used  by  nature,  i.  e.,  by  the  use  of  antitoxins,  etc. 
Hence  it  is  essential  to  know  something  as  to  the  chemistry  of  the 
antitoxins.  From  this  point  of  view,  we  recently  reviewed  the  lit- 
erature on  the  chemistry  of  diphtheria  antitoxin.2  As  a  result  of 
this  summary,  it  becomes  evident  that  there  are  two  views ;  one  is, 
that  the  antitoxin  is  not  necessarily  a  globulin,  but  is  carried  down 
with  them  on  precipitation ;  the  other  view,  held  by  most  workers, 
is  that  diphtheria  antitoxin  is  a  globulin,  and  some  uncorroborated 
work  even  suggests  that  ordinary  egg  globulin  could  be  converted 
into  diphtheria  antitoxin. 
We  have  been  carrying  on  experiments  to  determine  the  reaction 
of  diphtheria  antitoxin  to  various  reagents,  and  assuming  it  were  not 
a  globulin,  to  find  whether  it  could  be  separated  from  the  globulins. 
No  doubt  the  response  to  reagents  will  vary,  according  to  the  solu- 
tion in  which  the  antitoxin  occurs. 
For  part  of  this  work  we  have  used  unconcentrated  preparations 
obtained  through  the  courtesy  of  the  Cutter  Laboratory  at  Berkeley. 
The  first  preparation  contained  over  500  antitoxic  units  to  1  Cc.  It 
was  prepared  by  heating  a  mixture  of  70  parts  of  diluted  antitoxic 
serum  with  30  parts  of  saturated  ammonium  sulphate  solution,  i.  e., 
Banzhaf's  method.  The  second  preparation  was  simply  a  solution 
of  the  precipitate  from  antitoxic  serum  by  from  30  to  50  per  cent, 
saturation  of  ammonium  sulphate.  It  contained  450  units  to  1  Cc. 
The  third  preparation  was  a  concentrated  globulin  solution  (40,000 
units  in  about  13.5  Cc).  This  was  prepared  by  a' modified  Banzhaf 
method  and  was  given  us  by  Parke  Davis  &  Co.  The  fourth,  was 
a  globulin  preparation  from  the  Cutter  Laboratory  and  contained 
250  units  per  1  Cc. 
1  The  expense  of  this  work  was  partly  covered  by  a  grant  from  the  Com- 
mittee on  Therapeutic  Research  of  the  Council  of  Pharmacy  and  Chemistry 
of  the  American  Medical  Association. 
2  Crawford,  A.  C,  and  Foster,  M.  G.,  Biochem.  Bull.,  1917,  vol.  6,  p.  1. 
