Operating the Electrospray
4–5
Table 4-1
Selected Proteins and Their Diameters
Protein Diameter
(nm)
Ubiquitin
3
Bovine Serum Albumin
6.5
Ferritin 12
S t a r t i n g U p t h e E l e c t r o s p r a y
After the Electrospray system has been set up (see Chapter 2,
“
Unpacking and Setting Up the System
”) and samples have been
made, follow this procedure to begin generating aerosols:
1.
Turn on the power switch on the back panel. Make sure the
power and high-voltage LED’s are on and check the viewing
window to make sure the capillary tip is near the center of the
viewing window.
2.
Remove the bottom half of the pressure chamber by twisting it
1
⁄
8
-turn counterclockwise. The bottom half can then be removed
by pulling downward.
Note
: High voltage is turned off if the bottom half of the pressure
chamber is removed.
3.
Insert and open the sample vial as shown in Figure 4-1. Use
caution not to contaminate the sample.
4.
Replace the bottom half of the pressure chamber by aligning the
grooves to the pins in the top half and pushing the bottom half
upwards, making sure the capillary and platinum wire are
aligned with the sample vial. As the pins enter the grooves,
continue pushing upwards while turning the bottom half
clockwise until the bottom half locks in place.
!
W A R N I N G
The capillary and platinum wire are adjusted for use with a 1.7 mL
centrifuge tube, if it is necessary to use a different sized vial, see
Chapter 5, “
” for instructions on adjusting the capillary and
platinum wire positions to avoid breaking the capillary or damaging the
platinum wire.
