Understanding Fixatives in Biological Sample Preservation

Fixatives are substances that are used to stabilize or preserve biological samples, such as cells, tissues, or proteins. They are typically added to the sample after it has been fixed, which means that the sample has been treated with a chemical that prevents the breakdown of the molecules in the sample. This allows the sample to be preserved for a longer period of time and makes it easier to study the structure and function of the molecules in the sample using various techniques such as microscopy, western blotting, or mass spectrometry.

There are many different types of fixatives that can be used depending on the type of sample being studied and the technique being used to analyze it. Some common fixatives include:

* Paraffin: This is a waxy substance that is often used to preserve tissue samples. It helps to maintain the structure of the tissue and makes it easier to section the tissue into thin slices for microscopic analysis.
* Formaldehyde: This is a strong fixative that is commonly used to preserve cells and tissues. It cross-links the proteins in the sample, which helps to preserve their structure and function.
* Glutaraldehyde: This is another common fixative that is often used to preserve cells and tissues. It is particularly useful for preserving samples that will be analyzed using electron microscopy.
* Alcohols: Ethanol and methanol are both commonly used as fixatives for preserving cells and tissues. They help to preserve the structure of the sample and make it easier to store and transport.

Overall, the choice of fixative will depend on the specific needs of the experiment and the type of analysis being performed. It is important to choose a fixative that is appropriate for the sample being studied and that does not interfere with the technique being used to analyze it.