Simplified fixative medium for direct immunofluorescence in skin biopsies.

The main limitation for the use of direct immunofluorescence in skin biopsies was the necessity for frozen tissue. In 1973 Michel et al reported use of a liquid fixative, consisting of ammonium sulfate, N-ethyl-maleimide, magnesium sulfate, and potassium citrate, for handling skin biopsy specimens. The present study introduces a simplified liquid fixative medium consisting only of ammonium sulfate and saline. Comparisons of direct immunofluorescence findings in biopsy specimens transported in these two transport media and in fresh-frozen specimens revealed only minimal differences between the three different procedures.