For research use only. Not for use in diagnostic procedures.
Below is the cation exchange setup for the manual injection procedure when using the iTRAQ® reagent: A 22-gauge syringe with a 2-inch needle is recommended in the iTRAQ protocol, but the 2-inch needle is no longer available. So instead, an 18-gauge syringe with a 2-inch needle is recommended.
Here are some tricks and tips when setting up for manual injection of the cation-exchange column:
Using syringes with Luer-lock connections may help prevent leakage.
A 1-inch needle may not sit fully in the needle port adapter, so the 2-inch needle is recommended.
If something other than a blunt-end needle was used at any point, the tubing inside the needle point adapter may be torn.
The tubing inside needle point adapter might have been twisted or stretched (when doing what?).
The user might exert too much pressure on the plunger of the syringe.
The 18-gauge needle is a larger inner diameter than the 22-gauge.
Change ferrules both in and out and change outlet tubing. These may be crushed and causing back pressure (when do they need to be changed?).