SAINT-PhD protein delivery reagent has been tested together with 5 competing protein
delivery reagents. Cells were plated at a density of approximately 100 thousand cells/well
in a 24-well plate one day before protein transfection. Cells were confluent the next day.
FITC labeled F(ab’)2 Rabbit-anti-Mouse IgG was used as protein of choice, because the
delivery of this labeled protein can easily be monitored by FACS analysis. Each reagent was
used according to its manufacturers protocol. Cells were incubated with the protein complexes
for 4 hours (37°C,5% CO2) without changing the medium (containing 10% FBS). FACS analysis
was performed after harvesting the cells.

From figure 1 it is clear that SAINT-PhD is the only reagent that performs well when
delivering relatively small amounts of proteins into cells growing in serum containing medium.
It is our opinion that these two advantages are very significant for our customers.

The ability to deliver small quantities of proteins saves a lot of money, because most
proteins of interest are either very expensive or simply impossible to obtain in large quantities.
Furthermore, introducing large quantities of a certain protein in a cell will certainly disturb
the cellular machinery and will likely not resemble any type of naturally occurring event.
When studying naturally occurring processes, it is important to be able to deliver small amounts
of the protein to be studied.

The possibility to deliver proteins to cells in the presence of serum keeps the cells healthier
and more viable. And although the SAINT-PhD reagent is primarily meant for in vitro application,
the performance in the presence of serum suggests that also in vivo protein delivery might be
a possibility.

From this comparison of protein delivery reagents we conclude that our SAINT-PhD reagent is the
reagent best suited for intracellular protein delivery under physiologically relevant conditions.