Fluorescence microscopy with antisera against specific cellular structure: double photography method for cell identification in populations of multiple cell types

Immunofluorescent staining techniques using antitubulin antibody have been difficult to apply to meiotic tissue (testis) because of the large number of cell types present. Such techniques customarily use a fluorescent dye to counterstain nuclei, and this counterstain is hard to distinguish because of the fluorescence of the antitubulin. By counterstaining with dilute hematoxylin, we can photograph the same field using UV and then conventional illumination. This double photography allows us to identify precisely the many types of cells present, and it will be a useful tool for reexamining the staging of spermatogenesis.     

DENTAL EXTRACTION DURING DICUMAROL THERAPY

Extraction of 14 teeth in six patients taking dicumarol caused no unusual bleeding. Discontinuance of dicumarol prior to dental extraction should not necessarily be a routine procedure; in certain persons with a demonstrated strong tendency to recurrent thrombosis, dicumarol should be continued, based on the decision that the danger of clotting without the drug is greater than the danger of bleeding with the drug.     

Synthesis of Benzodioxinopyrroles as selective α2-adrenoceptor antagonists

A novel series of tetrahydrobenzodioxinopyrroles has been identified as potent and selective α₂-adrenoceptor antagonists. Convergent syntheses have been developed that allowed the preparation of analogues and their enantiomers. A compound of particular interest is the 5-fluoro substituted analogue (fluparoxan).     

Technical Considerations in the Preparation of Fluorescent-Antibody Conjugates

A comparison was made of (NH₄)₂SO₄, HCl, ethodin, and ethanol for fractionation of rabbit antiserum prior to conjugation with fluorescein isothiocyanate. Fractionation with the salt was found to be the method of choice from the standpoints of simplicity and recovery of antibody effective in conjugates prepared from the fractions. Effects of pH, temperature, dye-protein ratio, and molarity and type of buffer upon conjugation were studied. These technical factors were adjusted to produce conjugates for Corynebacterium diphtheriae which possessed higher specific titers than did reagents obtained by previously employed techniques.