TIP2k syringe blocked

Problem

• TIP syringe is harder to operate than usually.

Solution

Start immediately with extensive cleaning procedures MiPNet12.10. Once a needle is totally blocked it is usually impossible (with exceptions) to clean it.

• Suitable solvents for extensive cleaning procedures depend on the substances used.
• Chloroform was successful for some fatty acids. An ultrasonic bath may be helpful in cleaning partially blocked syringes.

Reason and Prevention

1. To prevent washing out effect when the needle is inserted into the chamber the inner diameter of the TIP needle has to be very small. This means that the needle is easily blocked by small particles either precipitated from the solution or introduced with the solution.
2. While a TIP syringe has to be considered a consumable, it is possible to lengthen its lifetime by carefully following the procedures suggested in the TIP-2k Manual MiPNet12.10.

• The main way to prevent clogging of needles is to follow rigorously the cleaning procedure outlined in MiPNet12.10 after each usage.
• Additionally, it has to be taken care that no particles are suspended in the used solutions.
• For not very well soluble substances, filtering of the solution may be necessary. Small particles can also be introduced by laboratory activities, e.g. from paper towels or from powdered gloves. Only use underpowered gloves when working with TIP syringes!

Examples for proper TIP use and cleaning protocols:

A.) you want to do a instrumental O2 background (dithionite in phosphate buffer)

1. clean (fill and empty) the syringe with water
2. fill the syringe with dithionite solution that you discard immediately
3. fill the syringe with dithionite solution (in buffer) and use it in the experiment
4. after the experiment empty out the syringe and immediately clean the outside of the needle with water (because there is medium sticking to the outside)
5. fill and empty the syringe three times with water
6. you can store the syringe now (will be partially filled with water) or after cleaning with ethanol (then it will be partially filled with ethanol.

B.) you want to do a FCCP titration (FCCP in ethanol)

1. clean (fill and empty) the sysrineg with pure Ethanol
2. fill and empty with ethanolic FCCP solution (in this case more important than in example 1 because you want to have a precise FCCP concentration)
3. fill with ethanolic FCCP solution and perfrom the experiment
4. after the experiment empty out the syringe and immediately clean the OUTSIDE of the needle with water (because there is medium sticking to the outside)
5. clean (fill and empty) the syringe three times with ethanol
6. store the syringe now (will be partially filled with ethanol) or wash it with water and then store (then it will be partially filled with water)