B5 FIXATIVE, 1000 mL

PRINCIPLE

Tissue fixation by chemical methods aims to interrupt the degradation processes that occur after cell death, in order to preserve the structure and composition of the tissues as much as possible.

Fixative agents have the ability to stop the process of tissue autolysis, denature proteins, and inactivate enzymatic activity.

Some fixatives may also act as preservatives, but indefinite preservation cannot always be guaranteed. Fixation is not synonymous with tissue preservation.

Types of Fixation: Depending on the type of assay and staining to be performed, two procedures are distinguished.

1. Histological fixation: primarily preserves the structure, regardless of whether there is any alteration in biochemical components.
2. Histochemical fixation: aimed at preserving molecular composition to the greatest extent possible.

It is important to note that a particular fixative agent may be suitable for certain types of tissues but may not provide optimal results with others. Therefore, there is no universal fixative that is ideal for all working situations. The appropriate product must be used depending on the type of process, tissue, and study for each specific situation.

Usage. Operating Characteristics

Fixation of tissues for the observation of nuclear details. Ideal for lymphoid and hematopoietic tissue. It is the fixative of choice for kidney, liver, and studies of connective tissue and fibrin.

The working solution, which is unstable, should be prepared at the time of use by adding one part of concentrated Formalin (37–40%) to 10 parts of the reagent.

Due to its low penetration rate, the thickness of the samples should not exceed 4 mm, and the fixation time should not exceed 4 hours.

It is not a good preservation medium. After fixation, it is recommended to store the tissue in 70–80% ethanol.