Hello Seth,

For our uses of BME in the biosafety cabinets in SSPPS and elsewhere on campus:

1) For tissue culture media, usually of mouse splenocytes or other lymphocytes or macrophage lines, the BME concentration in the media is usually around 50 micromolar (range 50 - 200 micromolar). The 14.2 M BME stock bottle is opened only in the fume hood and used to make a 100X stock in DPBS--this is approximately a 1:3000 dilution of the stock bottle--which is then sterile filtered in the biosafety cabinet. The 100X stock is then opened in the biosafety cabinet only long enough to withdraw the amount for the media. Some people contend that the BME needs to be added to the media fresh every day, but for our cells it didn't seem to matter. So for most routine culture of the cells, the media contains only a 1:300,000 dilution of the stock bottle and the BME is not detectable by nose. 

2) For the viral work, virus or virus infected cells will be solubilized in sample buffer containing 5% (v/v) BME [final] to inactivate infectivity (along with the SDS) before moving samples out of the biosafety cabinet. Since this is a 1:20 dilution of the stock bottle, it does have a strong smell so tubes containing the sample buffer are only opened long enough to withdraw the buffer. No flame is present during this work.

So, exposure levels to BME are low in case #1 and brief in case #2, so safety concerns are mitigated as much as practical, and in the case #2, we worry much more about pathogenic human viruses.

Hope this helps,

Chris

Beta-mercaptoethanol is very smelly, and your lab mates will not be happy with you if you fill the lab with it. Use it in an externally vented fume hood. Or use something less volatile as a reducing agent, such as TCEP or DTT.

http://www.sciencelab.com/msds.php?msdsId=9924612

Here is an MSDS for BME. You probably wouldn't create a real safety hazard, but it is interesting to see these words in the MSDS:

Potential Acute Health Effects:

Very hazardous in case of skin contact (permeator), of ingestion. Hazardous in case of skin contact (irritant), of eye contact

(irritant), of inhalation. Severe over-exposure can result in death.

Hello Seth,

For our uses of BME in the biosafety cabinets in SSPPS and elsewhere on campus:

1) For tissue culture media, usually of mouse splenocytes or other lymphocytes or macrophage lines, the BME concentration in the media is usually around 50 micromolar (range 50 - 200 micromolar). The 14.2 M BME stock bottle is opened only in the fume hood and used to make a 100X stock in DPBS--this is approximately a 1:3000 dilution of the stock bottle--which is then sterile filtered in the biosafety cabinet. The 100X stock is then opened in the biosafety cabinet only long enough to withdraw the amount for the media. Some people contend that the BME needs to be added to the media fresh every day, but for our cells it didn't seem to matter. So for most routine culture of the cells, the media contains only a 1:300,000 dilution of the stock bottle and the BME is not detectable by nose. 

2) For the viral work, virus or virus infected cells will be solubilized in sample buffer containing 5% (v/v) BME [final] to inactivate infectivity (along with the SDS) before moving samples out of the biosafety cabinet. Since this is a 1:20 dilution of the stock bottle, it does have a strong smell so tubes containing the sample buffer are only opened long enough to withdraw the buffer. No flame is present during this work.

So, exposure levels to BME are low in case #1 and brief in case #2, so safety concerns are mitigated as much as practical, and in the case #2, we worry much more about pathogenic human viruses.

Hope this helps,

Chris

Thanks very much for the responses!