Vital stain

A vital stain in a casual usage may mean a stain that can be applied on living cells without killing them. Vital stains have been useful for diagnostic and surgical techniques in a variety of medical specialties.^[1] In supravital staining living cells that have been removed from an organism, whereas intravital staining is done by injecting or otherwise introducing the stain into the body. The term vital stain is used by some authors to refer to an intravital stain, and by others interchangeably with a supravital stain, the core concept being that the cell being examined is still alive. But in a more strict sense the term vital staining has a meaning contrasting with supravital staining. While in supravital staining the live cells take up the stain, in "vital staining" - the most accepted but apparently paradoxical meaning of this term, the live cells exclude the stain i.e. stain negatively and only the dead cells stain positively and thus viability can be assessed by counting the percentage of total cells that stain negatively. Very bulky or highly charged stains that don't cross live plasma membrane are used as vital stains and supravital stains are those that are either small or are pumped actively into live cells. Since supravital and intravital nature of the staining depends on the dye, a combination of supravital and vital dyes can also be used in a sophisticated way to better classify cells into distinct subsets (e.g. viable, dead, dying etc.).

List of common vital stains

• Eosin dye exclusion^[2][3]
• Propidium iodide, DNA stain that can differentiate necrotic, apoptotic and normal cells.^[4]
• Trypan Blue, a living-cell exclusion dye
• Erythrosine, which is Red No. 3 in food coloring, can be used as an exclusion dye.
• 7-Aminoactinomycin D used e.g. in flowcytometric studies of hematopoietic stem cell viability.

See also

• Cytopathology
• Histology
• Staining
• Viability assay

References

1. ↑ Rodrigues EB, Costa EF, Penha FM, Melo GB, Bottós J, Dib E, Furlani B, Lima VC, Maia M, Meyer CH, Höfling-Lima AL, Farah ME (2009). "The use of vital dyes in ocular surgery". Survey of Ophthalmology 54 (5): 576–617. doi:10.1016/j.survophthal.2009.04.011. PMID 19682624. 
2. ↑ Hathaway WE, Newby LA, Githens JH (1964). "THE ACRIDINE ORANGE VIABILITY TEST APPLIED TO BONE MARROW CELLS. I. CORRELATION WITH TRYPAN BLUE AND EOSIN DYE EXCLUSION AND TISSUE CULTURE TRANSFORMATION.". Blood 23 (4): 517–525. PMID 14138242. 
3. ↑ Keren DF (2001). "Section X: Immunopathology". In McClatchey KD. Clinical Laboratory Medicine (2nd ed.). Lippincott Williams & Wilkins. p. 1384. ISBN 0-683-30751-7. 
4. ↑ Lecoeur H (2002). "Nuclear apoptosis detection by flow cytometry: influence of endogenous endonucleases". Exp. Cell Res. 277 (1): 1–14. doi:10.1006/excr.2002.5537. PMID 12061813.