The complement fixation test in syphilis, commonly known as the Wassermann test.

  • Great Britain. Ministry of Health.
Date:
1920
Catalogue details

Licence: Public Domain Mark

Credit: The complement fixation test in syphilis, commonly known as the Wassermann test. Source: Wellcome Collection.

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    but also that the behaviour of a complement towards antigen alone is no indication of what will happen when it is brought into contact with the serum-antigen complex. It is for this reason that, in the method of conducting the Wassermann test which is proposed in this paper, the amount of complement- containing serum is kept constant, a departure from the usual technique of the present day, in which the quantity of guinea- pig serum employed in the test is determined by the hemolytic titre, both alone and in the presence of antigen. Probably more discussion has raged over the properties of different “antigens” than over any other single constituent of the Wassermann test. Broadly, there are those who prefer plain extracts; those who fortify these with cholesterin ; those who remove the acetone-soluble fraction of plain extract on the grounds of its containing undesirable compounds in variable amount; and those who use only the acetone-soluble fraction. Against the plain extract and the acetone-insoluble fraction is the contention that they fail to detect an important proportion of syphilitic sera. Against the addition of cholesterin to plain extract it is said that this is liable to result in false positives ; although this may not be true of such “antigens” when employed with adequate controls and when fixation takes place at 37°°C., it is certainly true when the method of prolonged fixation at ice-chest temperature is employed, as numerous tests carried out by Captains Wyler and Balthasar, R.A.M.C., at my suggestion, have shown. As.a result of the present research, Doctors Griffith and Scott have concluded that one of the undesirables in the acetone-soluble fraction of a plain extract is its variable content of cholesterin; and that one of the main disadvantages of the acetone-insoluble fraction advocated by Noguchi is that, lacking cholesterin, it is not such a delicate reagent as it is desirable to employ in this test. The authors propose, therefore, to remove the natural cholesterin from the plain extract (along with undesirables which, like cholesterin, are soluble in acetone) and then to add cholesterin in the amount which is found by experiment to be appropriate. This seems to go far towards the production of a standard antigen which is both delicate and reliable. At the same time the different behaviour of “antigens” prepared from the same materials, which is disclosed by. this research, indicates that comparative statistics on the subject should be based on tests conducted with the same “antigen.” The desirability of issuing such an “antigen”’ from a central source is supported, also, on the ground that considerable labour is involved in its preparation and standardisation. As to the method of preliminary fixation, there is much to recommend prolonged fixation in the ice-chest. Dean has shown that fixation at ice-chest temperature, though slower, is more complete than fixation at 37° C., which, in the time allowed, is apt to miss the slowly-fixing serum-antigen com-