Autofluorescence can be a major problem in some tissues and be hard to distinguish from a specific fluorescent staining. Autofluorescence can have different causes. One source of autofluorescence can be naturally fluorescent proteins such as lipofuscin, elastin or collagen that are expressed in certain tissue types. Another cause of autofluorescence is the fixation of tissues using aldehyde based fixing methods such as Formalin, Glutaraldehyde or Paraformaldehyde (PFA). The MaxBlock Autofluorescence Reducing Reagent Kit helps to reduce autofluorescence from different causes.