Protocol Online logo
Top : New Forum Archives (2009-): : Cell Biology

EDTA not working!! - (Dec/07/2009 )

Hi,
I've tried various concentrations of EDTA (up to 0.04%) and my cells just won't come off. If I leave them in the incubator for about 10mins, they do come off, however I do notice a lot of cell damage. Any ideas? Should I increase the concentration up to 0.25%?

Many thanks

-themoon-

Just plain EDTA? Most people use trypsin(or other enzyme)-EDTA

-bob1-

I agree w/ bob1 that most times a combination of Trypsin and EDTA is called for....unless you're staining for a surface marker. Assuming the latter case, have you washed your cells with Ca2+/Mg2+ free PBS or HBSS first? Usually a trypsin/EDTA solution has the EDTA at 0.53mM, (=155 g/l or 0.155%), so maybe more would help. It may not hurt to make sure the pH is near neutral, since EDTA solutions are generally rather alkaline (pH>8)

-jah-

jah on Dec 7 2009, 07:55 PM said:

I agree w/ bob1 that most times a combination of Trypsin and EDTA is called for....unless you're staining for a surface marker. Assuming the latter case, have you washed your cells with Ca2+/Mg2+ free PBS or HBSS first? Usually a trypsin/EDTA solution has the EDTA at 0.53mM, (=155 g/l or 0.155%), so maybe more would help. It may not hurt to make sure the pH is near neutral, since EDTA solutions are generally rather alkaline (pH>8)



I was thinking of using the combo, however I think the tryp may be too harsh. I need to keep the surface proteins intact. Yes, I wash my cells with PBS free of divalent cations. Hmm I think I may need to try EDTA at 0.1% then. What concentration is the trypsin at in the trypsin/EDTA combination?

Thanks very much for your help guys! Really appreciate it!

-themoon-