The molecular analysis of formalin-fixed and paraffin-embedded tissues has application in both investigative studies and clinical practice (1). It is now possible to analyze gene expression in formalin-fixed and paraffin-embedded tissues by in situ reverse transcriptase-polymerase chain reaction (in situ RT-PCR) (2). Degradation of RNA, however, can occur at various stages of tissue preparation...

A new monoclonal antibody (JK-199) was found to react with basement membranes on paraffin-embedded tissue sections without prior enzyme digestion. JK-199 was shown to react with isolated type IV collagen treated by any of four different fixatives--PLP, 4% formalin, modified Zamboni's (0.2% picric acid, 4% paraformaldehyde in 0.1 M phosphate buffer, pH 7.4) or Bouin's--applied for 6 h at room te...

Development and standardization of reliable methods for detection of Mycobacterium tuberculosis in clinical samples is an important goal in laboratories throughout the world. In this work, lung and spleen fragments from a patient who died with the diagnosis of miliary tuberculosis were used to evaluate the influence of the type of fixative as well as the fixation and paraffin inclusion protocol...

A fluorescein isothiocyanate (FITC) technique and one based on peroxidase-antiperoxidase (PAP) were used to study the distribution of immunoglobulin (Ig) in cryostat and paraffin sections of human tonsil. Trypsin and other proteolytic enzymes were used to 'unmask' the antigen in paraffin sections. The effects of processing, and particularly of fixation, on the immunohistochemical response of ti...

Molecular diagnostics in personalized medicine increasingly relies on the combination of a variety of analytical technologies to characterize individual diseases and to select patients for targeted therapies. The gold standard for tissue-based diagnostics is fixation in formalin and embedding in paraffin, which results in excellent preservation of morphology but negatively impacts on a variety ...

Paraffin wax has been exploited in microactuators because it exhibits a volumetric expansion of ∼15%, at around its melting point. In order to nderstand paraffin wax actuation, for the first time, the melting process has been investigated using a combination of analytical modelling (using tefan’s problem and Neumann’s solution), finite element method (FEM) simulations and actuation data from me...

Limited data exist in regard to productivity and staffing in the anatomic pathology laboratory. In 2004, the National Society for Histotechnology (NSH) conducted a pilot study to examine productivity and staffing in the histology laboratory. After review of the data, The College of American Pathologists (CAP)/NSH Histotechnology Committee concluded that a larger survey was required to further a...

We have micromachined and tested the first paraffin–PDMS composite thermal microactuator having multi shot large vertical displacement capabilities (~160 μm for 1 mm diameter device). A solid to liquid phase change of trapped paraffin into the PDMS is used to create a large volume dilatation of the composite (18%, for a temperature varied from 20 to 80 °C). The elasticity of the PDMS ensures th...

Autophagy assures cellular homeostasis, and gains increasing importance in cancer, where it impacts on carcinogenesis, propagation of the malignant phenotype and development of resistance. To date, its tissue-based analysis by immunohistochemistry remains poorly standardized. Here we show the feasibility of specifically and reliably assessing the autophagy markers LC3B and p62 (SQSTM1) in forma...

Frozen tissue specimens are the gold standard for molecular analysis. However, snap freezing presents several challenges regarding collection and storage of tissue, and preservation of histological detail. We evaluate an alternative preservation method, ethanol fixation followed by paraffin embedding, by analyzing expression profiles of microdissected cells on Affymetrix oligonucleotide arrays ...