Comparative Study of Micro Infrared Techniques

A comparative study was made of several techniques used in the isolation and identification of microgram quantities of drugs by infrared spectroscopy. The isolation techniques include preparative GLC and TLC. In the case of TLC, silica gel interference was nearly eliminated by using a sintered glass filter and vacuum. The identifications were enhanced by concentrating the sample in the infrared beam center. The sample was centered either with the aid of a cardboard silhouette or punched out or drilled indentations in the disk.

PREPARATION OF A STABLE NONINFECTIVE GROUP-SPECIFIC ADENOVIRUS DIAGNOSTIC ANTIGEN

In the preparation of a group-specific diagnostic antigen for adenoviruses, various procedures for the concentration and purification of the antigen present in the tissue culture fluid of specifically infected cells were investigated. It was found possible to prepare an antigen of increased potency and specificity by passage of the fluid through an ultrafine sintered glass filter, followed by coprecipitation of the antigen with copper hydroxide. This antigen was rendered noninfective by treatment with 0.01% formaldehyde at pH 7 at 37 °C for 4 days or by heating at 56 °C at pH 5.5 for 3 hours. After destruction of the infectivity the antigen was stabilized for storage by lyophilization. This antigen, after such treatment, still retained its serological reactivity.

POLARIZATION STUDIES IN COLLODION MEMBRANES AND IN SYNTHETIC PROTEIN-LIPOID MEMBRANES

1. Collodion membranes of high polarizability and low resistance can be obtained either by addition of certain ether-soluble substances such as phosphatides, olive oil, mastix, and gum benzoin, to the collodion or by drying collodion membranes for a limited time under pressure. 2. The permeability of membranes of different polarization has been measured by means of conductivity methods. 3. Sintered glass filter plates of Jena glass crucibles on which proteins and lipoids have been adsorbed show polarization. It could be shown that some narcotics which react with lecithin cause an increase in polarization of the protein-lipoid-glass system. Substitutions of the protein but not of the lipoid were possible, without causing a decrease in the polarizability of the membranes.