As far as I'm concerned, when i worked with hESC, Pen/strep was added to hESC media at a concentration of  100U/mL - 0,1mg/mL .

Will it interfer?? Everything interfer with hESC it's a question of benefit/risk balance, maybe u should check first if it is a big deal in the problematic you are working on.

a link http://xenopus.rockefeller.edu/pdf/brivanlouprotocols.pdf

Good luck

Hello

if I work with care in aseptic conditions, you not need antibiotics ... but I think that you might run the risk of the pen/strep not fully dissolving in culture medium, as culture medium already has a multitude of salts and nutrients already dissolved in it  this is just a guess . but if youre room for cell cultures is not the best room to do that , use antibiotics as the only solution to you

usually recommended to use 100 units/ml of penicillin and 100ug/ml of Strep. I have each other in powder so... I have to take the exact quantity and put directly to the medium and then filter all...or is better to have aliquots of penicillin and use this aliquots for adding to the medium and then filter .

you have prepare P/S with water, sterile filter and freeze aliquots at -20ºC untill their use at 5ml/tube for 500 of medium or 10ml for 1l of medium. If you buy the sterile medium in 500 ml bottles, you add the sterile P/S to the sterile medium, but if you prepare your own medium from powered components, you can add solid P/S and sterilize by 0.22um filter all together.As the commercial sterile medium comes in 0.5 l bottles, everybody add the 50ml of serum and the 5ml of antibiotics sol, having a final volume of 555ml .

Good luck

You may use 1X pen/strep from a stock 100X strength (Gibco, Cat# 15140-122). It is preferable to first perform a dose-response test to determine the level at which toxicity begins. 

Hi Vinc :) 

According to Stemgent protocol, they recommend ( as optional step) adding 5 ml of Pen/Strep(100x) for each 500 ml of medium. 

Pen/strep available at GIBCO   cat No# 15070-063

Hello

we are working with antibiotics in the culture media (Pen/Strep) and as well for selection of genetically modified cell clones and the growth rates seem to be equal to a cultivation without antibiotics (performed from colleagues of us).

If there are any differences or if it could interfere depends on the planed experiments. Thus, I would definitely suggest you to test if the added antibiotic may alter the outcome of your particular experiment (like already mentioned before) by direct comparison of the two conditions (with and w/o antibiotics).

There are a lot of different companies that have a Pen/Strep or an antibiotic/antimycotic mix in their portfolio with an exact description how to use it (often used in a final concentration of 50-100 U/ml penicillin and 50-100µg/ml in the culture medium).

Best greetings

Best not to for routine maintenance. However, for differentiations procedures it is often added since they can take many weeks. For example, I'm pretty sure that either N2 or B27 contains Pen/Strep for neural differentiation procedures and thus can not be inhibitory for this.