The Kahn Test. A Practical Guide

This article is only available in the PDF format. Download the PDF to view the article, as well as its associated figures and tables. Abstract In the preface, Dr. Kahn states that this is practically a new edition of that part of his previous book, "Serum Diagnosis of Syphilis by Precipitation," covering procedure. This statement is entirely too modest and does the book an injustice, for the first third of it is given over to an introduction which is by far the most interesting part. It gives a clear and highly instructive presentation of the facts that led up to the Kahn test. The difference between the specific immunity precipitation and that occurring with syphilitic serum, the effect of concentration of reagents, the quantitative relation between antigen and saline solution, demonstrating the zone phenomena, the effect of shaking, the dilution of antigen suspension and serum mixture, are all discussed separately. Their meaning is then brought out in a summary showing that they follow the rules of colloid reactions. Reasons are given for the assumption that