Why add phenol red in trypsin? - (Apr/27/2005 )
anybody can tell me that should we use phenol red contained in our trypsin-EDTA 0.05% for the purpose to trypsinize my keratinocyte monolayer cell line??
thanks!!
You don't have to use phenol red in the trypsin, it just helps ensure that you have the right pH, as too high or too low a pH will do more damage to the cells when they are in a fraglie state, such as when they are being trypsinised.
bob
o, i see..the phenol red as a pH indicator as what u mentioned. thus, it gives the red color of the trypsin-EDTA. i'm wondering to know why they added in the phenol red in trypsin?? is that just giving the red colour...and to adjust the pH of the trypsin-EDTA???
i tend to order trypsin-EDTA from Gibco,, but it contains phenol-red...will it do much problem to my adherent monolayer cell line???
thanks!!!
hi
according to the fact most of the mediums used in cell culture contain phenol red too, i don't think that will poison your cells.
you're right. that's an information for you too as bob said.
fred
fred, u meant it doenst matter if we have phenol red contained in our trypsin EDTA. ??
stilll yet, wondering why some manufacturers put in phenol red in medium and trypsin EDTA since they can just neglect the addition...right???why is that??
thanks!!
i agree with the fact it doesn't mattter if there's phenolred in trypsin edta.
But i disagree with the fact phenol red (or other ph indicator) is negligible in medium. Most of the time, it doesn't deserve special thing except indicate pH, but for me i use it for detecting cell clones in a 96 well plate too and to check part of the health of cells.
BTW, i think ph indicator is quite essential information in cell culture...
Pheol red is used in the trypsin-EDTA and medium as a pH indicator only (at least as far as i know), it is really useful for a quick visual check of the pH of the solutions, if they are purple the pH is too high, and yellow if the pH is too low and in both cases should be discarded.
Not all commercially made medium contains phenol-red, you can even buy DMEM without it. Phenol red is an estrogen analogue, that can (and does) mimic the action of adding estrogen to a cell line. If you are doing work that involves estrogen treatment, then use media and trypsin without phenol red.
If you are really worried about it, you can buy powdered trypsin and make up the solution yourself.
Bob
Thanks Fred and Bob, i guess it should be much useful basically for visual observation on cells conditions, at least it raises up color.
phenol red contained in either medium or trypsin should be less enough in order not to affect cells growth. so, here can be concluded that no big deal using phenol red in small quantity either in medium or trypsin as it performs as indicator,and not to harm cells growth as main.
thanks!!
Is Trypsin/EDTA a detergent?? 
No. 
Trypsin is an enzyme that nibbles away at the cell's protein anchorage to the plate. EDTA chelates Mg ions, causing the cell to round up. Both in concert cause a cell to detech from the plate.