Fixed tissue — Fix tissue in 10% formalin in a concentration 10 times the volume of tissue to ensure effective fixation and to reduce potential of infectious contamination. However, the viability of infectious organisms is dependent on a host of variables that have not been clearly identified, and fixed tissue has been shown to remain infectious (78). M. tuberculosis has been transmitted from fixed specimens as well as grown from fixed specimens, and CJD is not inhibited by the routine concentration of formalin. Grossing stations where formalin-fixed specimens are cut are designed for decreasing the fumes of formaldehyde but are not BSCs (2,57,83–85). Formalin-fixed specimens must be handled with gloves.--Transmissibility of the prion is retained in formalin-fixed paraffin blocks .FROM《Guidelines for Safe Work Practices in Human and Animal Medical Diagnostic Laboratories 2012 CDC and BBRP》。