In histopathology, tissues must undergo timely and effective fixation before subsequent embedding and sectioning. The functions of tissue fixation are to preserve the inherent morphology and structure of tissues and cells, prevent bacterial decomposition and autolysis of tissue cells, retain intrinsic cellular substances, coagulate intracellular proteins, minimize or terminate the reactions of endogenous and exogenous enzymes, and maintain the substances within cells or tissues nearly identical to their in‑vivo state. It also hardens tissues to facilitate trimming. For certain infectious specimens, fixation prevents the spread of pathogens and preserves gross specimens. Finally, fixation can improve staining performance.
In clinicopathological experiments, fixatives are mainly classified into aldehyde fixatives, mercury‑based fixatives, alcohol fixatives, oxidant fixatives, and picrate fixatives. Among them, formalin (aldehyde‑based) and ethanol (alcohol‑based) are widely used. Formaldehyde is one of the most common fixatives. It features strong penetration, uniform fixation, low tissue shrinkage and proper hardness, and is suitable for most tissue samples.
Muscle Fixative consists mainly of absolute ethanol, glacial acetic acid and formalin, and is specially designed for fixation of muscle tissues. Compared with conventional fixatives, this product can reduce muscle tissue splitting and deliver high‑quality muscle tissue sections. It contains an extremely low level of formaldehyde and provides higher safety than commonly‑used 10% neutral buffered formalin fixative; hence it is also known as eco‑friendly muscle fixative.
This product is for research use only and is not intended for clinical diagnosis or other applications.
Operating Procedures (For Reference Only)
1. Immediately place freshly‑dissected muscle tissue into muscle fixative. The volume ratio of fixative to tissue shall be no less than 10:1.
2. Fix at room temperature for 6‑24 hours, then transfer to 75% ethanol for preservation or transportation.
Precautions
1. Muscle fixative is harmful to human body. Operate carefully in a well‑ventilated environment and avoid inhalation.
2. Tissues shall be fixed promptly right after dissection.
3. Fixation time varies with tissue thickness. Proper tissue sampling facilitates fixative penetration. The optimal thickness for routine biopsy tissues is 2‑4 mm, generally no more than 6 mm.
4. Sufficient volume of fixative is required; the volume ratio of fixative to tissue block should be greater than 10:1. If insufficient volume is available, replace the fixative 1‑3 times during fixation.
5. Temperature has a significant effect on fixation. Elevated temperature accelerates fixation, yet excessive temperature shall be avoided.
6. Tighten the cap promptly after use to prevent volatilization of active ingredients.
