Number
048-EN
Section
General Section
Use
Sector
Health services
Function
Other
Process
Other
Product category
laboratory chemicals
Application
Analysis of protein, DNA and RNA
Abstract
Methanol is used in a fixation process required for analysis of proteins and DNA/RNA on polyacrylamide gels. Fixation is necessary for transforming the proteins or nucleic acids into large, insoluble aggregates which are unable to react or degrade. Ethanol is a good substitute for methanol since it´s less toxic and therefore safer to work with.
The substitution does not work well with Western blot analysis's and processing of membranes. It should also not be used on PVDF-membranes.
Substituted substances
Methanol
CAS No. 67-56-1 EC No. 200-659-6 Index No. 603-001-00-X
Chemical group
Alcohols
Classification: hazard statements
H225 Highly flammable liquid and vapour
H331 Toxic if inhaled
H311 Toxic in contact with skin
H301 Toxic if swallowed
H370 Causes damage to organs
Other adverse effects
The substance is: neurotoxic cat. 4 (Vela et al.) as listed in the Substance Database according to SUBSPORT Screening Criteria (SDSC).
Alternative Substances
Ethanol
CAS No. 64-17-5 EC No. 200-578-6 Index No. 603-002-00-5
Chemical group
Alcohol
Classification: hazard statements
H225 Highly flammable liquid and vapour
Other adverse effects
The substance is: 1 carcinogen (IARC), as listed in the Substance Database according to SUBSPORT Screening Criteria (SDSC).
Reliability of information
Evidence of implementation: there is evidence that the solution was implemented and in use at time of publication
Reason substitution
other toxic effects
Hazard Assessment
Ethanol is highly flammable (H225). Methanol is on the Subsport Database Screening Criteria (SDSC) and holds the risk phrases H225, 23/24/25 and 39/24/25.
Description of Substitution
Methanol is used in the fixation of polyacrylamide gels in analysis of proteins and DNA/RNA. Fixation is necessary to transform the proteins or nucleic acids into large insoluble aggregates which are unable to react or degrade. Proper fixation is also required to get sharp protein band in electrophoresis. Ethanol is a good substitute for methanol in all applications except western blot analysis and processing of membranes. In these cases the polarity of ethanol disrupts the process.
Since methanol is far more toxic by inhalation and in contact with skin, ethanol works well as a substituent since it improves working place safety and makes the analysis easier to carry out.
Ethanol should also not be used on PVDF-membranes.
Methanol is toxic by inhalation and by skin contact; ethanol isn't and is therefore easier and safer to work with.
Ethanol is a polar compound and this can disrupt some analyses including western blot and membrane processing. The substituent does also not work well on PVDF-membranes.
The substitution does not require any changes in the process and the results of the analysis are not affected by the change of fixing agent. Note however that the substitution does not work well with western blot analyses and membrane processing due to the polar nature of ethanol. Also take care not to use ethanol together with PVDF-membranes.
Case/substitution evaluation
The use of ethanol instead instead of methanol is advantageous from a health and environmental point of view.
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
Available on the market.
Type of information supplier
User
Contact
https://www.folkhalsomyndigheten.se/the-public-health-agency-of-sweden/
Date, reviewed
February 27, 2020