hi,

the nonionic surfactant would be better than ionic ones. I think based on your oil, it is better to use 2 surfactant with high and low surfactant same as span and tween. However, please use surfactant with one family ( same fatty acids). span 80 with tween 80 and span 20 with  tween 20.

Thank you so much Shima!

you are welcome

'avoid any kind of diffusion of proteins and biomolecules from aqueous phase to oil phase'

Not so simple - first proteins and common biomolecules will not diffuse into the oil phase, however, will adsorb at the interface. If you apply fast adsorbing nonionic surfactant this will initially occupy the interface, but likely will be displaced by proteins on a longer time scale. Block copolymers may be able to prevent this because their diffusion kinetics are limited. Nevertheless, proteins will bind to the adsorbed block copolymer.

Hi Titus,

Thank you very much for your answer. In effect, there is the EA surfactant (RainDance Technologies, Lexington, MA), a PEG-PFPE amphiphilic block copolymer which might suit this need. However, I am not sure if this copolymer is also fine with mineral oil, which are hydrocarbon oils.

Thanks,

Giuseppe

Maybe common Pluronic PEO-PPO block copolymers with higher PPO content are better suited.

Hi Titus,

Following your suggestion, I would like to use Pluronic® L-121 or Pluronic® P-123, being PEO-PPO copolymers. I shoud check solubility in mineral oil, I think I shall use minute quantities of these surfactants in order to exert a certain effect. As a possible alternative, I would still consider the tweens or spans as from Shima' s suggestion. Especially I found tween20 to be effective if dissolved in the aqueous phase.

Thank you so much,

Giuseppe

Hi Giuseppe,

Are you open to using fluorinated systems (oils and surfactants)? If so, please connect with us at RAN Biotechnologies. We'ld be happy to suggest materials and methods of use.

www.ranbiotechnologies.com

Roger

Hi Roger, thank you so much for the message. Yes I am open also to using fluorinated systems as well as fluorosurfactants. Thank you for having introduced me RAN Biotechnologies.

Regards,

Giuseppe

Hi Giuseppe, Domenico Arrabito ,

I was wondering if you managed to produce stable drops using either Pluronic® L-121 or Pluronic® P-123 block polymer as surfactants? If not, what did you use than as your surfactant. Did the alternative with Tweens or Spans produce any satisfactory results? And also, did you use mineral oil, or some kind of perfluorinated oil?

Regards Leon

Just to follow up with more recent information, RAN Biotechnologies has recently introduced a new Chip-Free monodispersed droplet generation kit, and can save you on cost and time and without having to deal with microfluidic setup (chips/pumps/tubing/...). The kit is solely based on reagents. All you need is a pipette or a vortexer at the most in order to generate engineered droplets. Contact us at [email protected] or through our website, www.ranbiotechnologies.com