delivers proteins under physiologically relevant conditions.
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.
Figure 1: Intracellular delivery of FITC-labeled IgG with 6
different protein delivery
reagents. Each reagent was used according to the manufacturers
protocols. Cells were
incubated with the protein complexes for 4 hours (37°C,5% CO2)
without changing the medium.
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
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.