Abstract
In an earlier paper, Falk, Tonney, White and Jensen 1 reported some details concerning the use of a simple cataphoresis apparatus to distinguish toxigenic from non-toxigenic diphtheria bacilli. There are four shortcomings of the technique: (1) Use of pure cultures; (2) at least 48 hours'incubation; (3) three washings of the bacteria with distilled water; and (4) focussing the microscope on the “stationary level,” which have been eliminated by modification of the method.
We now cultivate the suspected culture from the swab on Löffler's blood serum at 37° C. for 12 to 24 hours. The growth is taken off with a sterile, clean wire loop or wooden applicators, and is emulsified in a little distilled water. A little of the emulsion is used for a stained preparation and examined under the microscope. If diphtheria-like organisms are observed, the remainder of the emulsion is used in the capillary tube of the new cataphoresis apparatus.
The principle of the simplified, capillary method was developed by Mooney. 2 The carefully cleaned tube (0.45-0.50 mm. outside and 0.15-0.25 mm. inside) is dipped into the bacterial suspension. It fills by capillarity. It is then laid across the electrodes in the simple chamber which had been previously filled with distilled water. The chamber is merely a rectangular glass dish with a pair of platinum electrodes bent to hold the capillary in a horizontal position.
Get full access to this article
View all access options for this article.