Trypsin/EDTA

[Kyle Legate]

DK wrote:
> In article <6dljquF36jrlU1 from mid.individual.net>, Kyle Legate <legatek from hotmail.com> wrote:
>> Lara wrote:
>>> Dear DK and Han,
>>>
>>> thanks so much for your helpful feedback. Indeed, now I understand it
>>> is not a waste of either Trypsin or EDTA. With responses like this
>>> newsgroups get another dimension in science. Thank a lot again!
>>>
>> It most certainly is a waste of trypsin/EDTA. If what DK says is true
> 
> Which is certainly true: it is an undeniable fact that serum contains
> alpha2-macrglobulin and medium contains ~ 2 mM of Mg2+ and 
> Ca2+.
> 

I'm not denying it. Clearly adding extra trypsin and then removing it 
dilutes inhibiting factors, but this practice was probably first 
suggested by a company to sell more product. It is not the better way. 
Washing with PBS is preferable because it more effectively removes the 
inhibitors (as you don't leave any behind in the flask when you aspirate 
all the PBS), and washing with PBS first removes dead cells and debris 
much more effectively.