WPI NANOLITER2020, Инструкция по эксплуатации

Страница: 24 / 44

20 World Precision Instruments
Micropipette Filling Techniques
Back Filling
“ Back filling” refers to the process of filling the pipette from the large, non-pulled end.
Back filling offers a great advantage when performing a bulk fill, because the large opening
allows you to use a syringe and MicroFil flexible needles.
1. Immerse a Luer syringe into the filling liquid.
2. Pull the liquid into the syringe. Attach a MicroFil needle onto the syringe.
3. Using the 34G MicroFil included, place the MicroFil needle into the micropipette
from the back side so that the needle’s tip is pushed all the way into the front part of
the pipette near the pulled end.
4. Eject the liquid into the micropipette and slowly withdraw the MicroFil needle as
the liquid fills the micropipette. Back fill the entire length of a glass micropipette. Be
careful to prevent bubbles. Wipe any excess filling liquid with a Kimwipe.
NOTE : This is how mineral oil is back-filled into glass micropipettes.
Front Filling
“ Front filling” describes the filling of a micropipette through the small, pulled front end of
the pipette. Front filling is achieved by creating a vacuum at the back end of the pipette
that pulls the filling liquid into the micropipette. Once the micropipette is installed on the
NANOLITER2020 Injector Head, it is possible to front fill. Front filling is advantageous for
small volumes of expensive samples.
Typical Filling Technique
The technique described below is a typical process for filling a micropipette with a small
volume of liquid for microinjection applications.
1. Back fill the micropipette with mineral oil.
2. Use the MICRO2T controller to eject the plunger from the home position. This is
necessary in order to allow the plunger to move backwards to create a vacuum for
front filling.
3. Install the micropipette in the NANOLITER2020 Injector. Then, submerge the
micropipette tip into the sample.
4. Pull the sample through the tip of the micropipette by moving the plunger of the
NANOLITER2020 Injector in the withdraw mode.