Traditionally, immunohistochemistry, immunoblotting, and histoblot have been 
used to detect protein in tissue samples. However, each of these techniques has 
a number of disadvantages. The sensitivity of protein detection in 
immunohistochemistry is lost due to fixation or paraffin embedding methods that 
modify antigenic sites. The anatomical resolution and specific cellular 
involvement are lost in immunoblotting. Histoblot, a hybrid of these two 
techniques, is able to resolve these issues, but it cannot be applied to 
formalin-fixed tissues. A recent technique, paraffin-embedded tissue (PET) blot, 
retains the superior protein detection and anatomical resolution of histoblot 
and is applicable to formalin-fixed tissues. Unfortunately, a major obstacle to 
the widespread application of PET is the lack of a detailed methodological 
description. In this paper, we describe a PET blotting method that was 
formulated from our own empirical and experimental research in Alzheimer disease 
and a systematic review of the current literature. From this, we conclude that 
PET can be applied to a variety of conditions with a wide spectrum of pathology.