Eosin 2 %, aqueous is a staining solution used in histology and cytology for staining cytoplasm, extracellular matrix and collagenous connective tissue. In combination with hematoxylin, which stains cell nuclei blue, hematoxylin-eosin (H&E) staining is performed, which is most commonly used in histological and cytological analysis.

Compared to other eosin concentrations such as 0.1% or 0.2%, a higher concentration such as 2% results in more intense staining and a shorter staining time. This higher concentration may be preferred in some cases to achieve more intense staining or to reduce staining time.

On the other hand, a lower concentration such as 0.5% or 1.0% may result in less intense staining and longer staining time. In some applications, this may be preferred to allow for more subtle staining or to better match staining time to experimental needs.

The choice of eosin concentration depends on the specific requirements and preferences of the user. It is important to determine the optimal eosin concentration for the particular application and desired staining effect. While a 2% aqueous eosin solution may be more appropriate in some cases, a lower concentration such as 0.1% or 0.2% may be sufficient or preferred in other situations.