Number
042-EN
Section
General Section
Use
Sector
Health services
Scientific research and development
Function
Reducing agent
Process
Use as laboratory reagen
Product category
laboratory chemicals
Application
Elecrophoresis
Abstract
This example concerns the substitution of 2-mercaptoethanol with 1,4-dithiothreitol for use as a reducing agent in sample preparations of proteins or DNA/RNA before electrophoresis.
Substituted substances
2-Mercaptoethanol
CAS No. 60-24-2 EC No. 200-464-6 Index No.
Chemical group
Thiols
Alternative Substances
1,4-Dithiothreitol
CAS No. 3483-12-3 EC No. 222-468-7 Index No.
Chemical group
Mercaptans
Reliability of information
Evidence of implementation: there is evidence that the solution was implemented and in use at time of publication
Reason substitution
skin/respiratory sensitizing
physical hazards
Hazard Assessment
The alternative and the substituted substance are not included in the database of hazardous substances according to SUBSPORTplus screening criteria (SDSC), and have no harmonised classification according to Annex VI of Regulation (EC) No 1272/2008 (CLP Regulation). » Check the Substance Database according to SUBSPORTplus Screening Criteria (SDSC)
Description of Substitution
2-Mercaptoethanol has been used as a reducing agent in sample preparation before electrophoresis. The function of the reducing agent is to remove the last remnants of tertiary and quaternary structure of the protein by breaking disulfide bonds, which in the absence of a reducing agent would be formed spontaneously. The disulfide bonds are covalent and can therefore not be broken without a reducing agent. Dithiothreitol can be used as a substitute for 2-mercaptoethanol in nearly all cases. Dithiothreitol is not as volatile and toxic as mercaptoethanol which means it is easier to work with as well as safer for the analyst. It is also significantly cleaner than 2-mercaptoethanol resulting in a higher accuracy in detecting and measuring bands in electrophoresis. Dithiothreitol in solution is slightly less stable than 2-mercaptoethanol. This means that it might be a good idea to use 2-mercaptoethanol when handling larger buffers to keep reduction capacity during a long time. Dithiothreitol is a good substitute for 2-mercaptoethanol in almost every case. When using especially large buffers 2-mercaptoethanol might be better to use because of its higher stability in solution. Dithiothreitol is also slightly more expensive than 2-mercaptoethanol.
Case/substitution evaluation
Since 2-mercaptoethanol is more volatile the alternative is both safer and easier to work with. In this case, the substitution has been successful but could have even higher demands in order to reduce the risk. It should however be handled with care.
State of implementation
Full capacity
Date and place of implementation
sweden
Enterprise using the alternative
Public Health Agency of Sweden https://www.folkhalsomyndigheten.se/the-public-health-agency-of-sweden/
Availability of Alternative
Alternative is available on the market.
Type of information supplier
User
Contact
Public Health Agency of Sweden https://www.folkhalsomyndigheten.se/the-public-health-agency-of-sweden/
Publication source: author, company, institute, year
Ionic liquids as an alternative to formalin in histopathological diagnosis. Agnieszka Pernak, Katarzyna Iwanik, Przemyslaw Majewski, Marian Grzymislawski, Juliusz Pernak. Acta histochem., 107 (2005) 149-156. http://www.sciencedirect.com/science/article/pii/S0065128105000334 Ionic liquids in embalming and tissue preservation. Can traditional formalin-fixation be replaced safely? Przemyslaw Majewski, Agnieszka Pernak, Marian Grzymislawski, Katarzyna Iwanik, Juliusz Pernak. Acta histochem. 105(2) 135-142 (2003) http://www.ncbi.nlm.nih.gov/pubmed/12831165
Date, reviewed
December 11, 2020