Diluting lipoid antigen with a constant dropping syphon.

Abstract

In order slowly and uniformly to dilute an alcoholic solution of tissue lipoids as required in such serologic methods as that of Meinicke, 1 an apparatus was desired that could easily and quickly be set to deliver water dropwise at a definite rate. Numerous trials by Kohler 2 indicated that the lipoid extract should be diluted in such fashion that seven volumes of distilled water are dropped into one volume of lipoid extract in twenty-eight minutes. A stable suspension of fine lipoid particles is formed, which obviously should be prepared as often as desired under identical conditions. The syphon herein described is simpler than the floating syphon used by Dreyer and Ward. 3

It delivers 49 cc. in exactly 28 minutes, but it can easily be set to deliver other amounts. From the figure the construction is almost self explanatory. The syphon itself is made by bending a piece of heavy wall soft glass tubing twice at right angles in the same plane. For convenience it is held in a rubber stopper perforated horizontally. Two capillary buret tips were attached to the limbs of the syphon with rubber tubing, glass ends in contact, so that the water flows through glass only. A broken thermometer stem was cut and attached to the short limb so that its lower end was a fraction of a millimeter below the capillary tip. By using detachable capillary tips, the limbs of the syphon may be cut if desired.