Formaldehyde substitute fixatives: effects on nucleic acid preservation.

Aims: In surgical pathology, formalin-fixed paraffin-embedded tissues are increasingly being used as a source of DNA and RNA for molecular assays in addition to histopathological evaluation. However, the commonly used formalin fixative is carcinogenic, and its crosslinking impairs DNA and RNA quality.

Methods: The suitability of three new presumably less toxic, crosslinking (F-Solv) and non-crosslinking (FineFIX, RCL2) alcohol-based fixatives was tested for routine molecular pathology in comparison with neutral buffered formalin (NBF) as gold standard.

Susceptibility to paratuberculosis infection in cattle is associated with single nucleotide polymorphisms in Toll-like receptor 2 which modulate immune responses against Mycobacterium avium subspecies paratuberculosis.

Paratuberculosis is a chronic intestinal infection in ruminants, caused by Mycobacterium avium subspecies paratuberculosis (Map). To study the role of host genetics in disease susceptibility, the Toll-like receptor 2 (TLR2) gene, selected based on its potential role in immunity to mycobacterial infections, was analyzed for single nucleotide polymorphisms (SNP) and their potential association with disease. For SNP discovery and to study SNP association with disease, a case-control study including 24 cows from farms with paratuberculosis was conducted.