1 This raw serum contained, apart from the desired AHG, other, unwanted antibodies to human red cell antigens, and, of course, complement.

2 Commercial companies took over much more of the AHG market, and the reagent became extremely avid and much more specific.

3 The AHG itself was also titrated in isotonic saline by a master doubling-dilution technique.

4 AHG membership consists of professionals, general members (including students) and benefactors.

5 The raw AHG we used was derived from sheep, some of which, I was told, were so old that they had to be fed parenterally (again, I may have been fooled into believing this by naivety).

6 This was then injected into the sheep, at different intervals, and, low and behold, the sheep made, amongst other things, raw AHG.