BL21A or simliar Options

[collitchboy]

My lab has recently started going through a lot of DpnI and I have found a source for the plasmid as well as a method of purification. However, the enzyme needs to be produced in a dam- cell line. The only IPTG inducable cell line I have found seems to be BL21A (DE3) but it was suggested by someone on another site that the person who wrote the paper/used the cell line also created the cell line. I have tried locating the author however the article is over 20 years old and I quickly hit a dead end. I have not been able to find it or an equivalent anywhere. I can find plenty of plasmid propagation cells that are dam- (INV110 SCS110 JM110 GM33) but I cannot seem to find a dam- protein expression line.

Does anyone know where I might be able to acquire BL21A (DE3) or an equivalent? Or can anyone suggest something else entirely?

Thanks so much!

[hanming86]

buy it or get it from some ppl working in molecular lab close to you.
BL21 (DE3) is a pretty common strain especially if the lab is working on protein expression.

[collitchboy]

I have plenty of BL21 and many derivatives. I cannot find BL21A which is a dam- expression line.