Hydrodynamic Tail Injection Process

1. Materials

Materials Size Details Manufacturer Trade marker
Millex filter 0.22um Simp025ss, quantity 50pk Millipore Millex
Needle 25Gx5/8 100, REF 305122 BD BD prescisionGlide™
Needle 26Gx5/8 Sub-Q 100, REF 305115 BD BD precisionGlide™
Syringe 3ml REF 309657 BD Luer-Lok™ tip
Syringe 10ml REF 309604 BD Luer-Lok™ tip
Saline
Tube 50ml BD
MICE fix container TV-150 Braintree Scientific INC, MA 02185
Red-ray Lamp

2. Tail injection

2.1 Plasmid solution preparation

  1. In most cases, we inject 20ug of “oncogene” into the mice, and SB is 1/25 of the total oncogene injected. For example, for AKT/Ras model, we need 20ug AKT, 20ug Ras and 1.6ug SB for each mouse.
  2. Calculate the plasmid needed to use in according to the dosage for the experimental design. Usually used 2ml/mouse (weight is about 20g when mice are at 6 weeks old), and the total volume is equal to (n+1) x2 ml, such as the mice number is 4, then need to prepare solution 10ml, namely (4+1)x2=10
  3. Filter the plasmids, after diluted the plasmid to the final volume, and mix well by shaking upside, then filter the solution to a new 50ml tube by filtering with 0.22ul filter. Be careful not to contaminate with other plasmids when more than 2 groups experiments. Mark the name and plasmids information on the tube.

2.2 Tail injection

    Take out 3ml syringe, load 2ml plasmid solution. Take one mouse from the cage, open the red-ray heater, and put the mouse tail under the heater for about 10-20 seconds, makes the tail vein easy to find. Fix the mice to the mice container, make mouth up, so that the mice do not easily move in the fixer, give the mice the plasmid through tail vein within 5-8 seconds.
Note
  1. About plasmid preparation
    1. When the plasmid concentration is too low, usually below 0.1ug/ml, then need to concentration, or deduced the volume from the total volume for tail injection.
    2. Freshly prepared plasmid solution for tail injection in the same day is better.
    3. Be avoiding of frozen- thawing plasmids too many times.

    For Maxi prep, we found the following kit is the best:

    Plasmid Maxiprep Kit :GenElute™ HP Endotoxin-Free Plasmid Maxiprep Kit; Part Number: NA0410

  2. About injection
    1. Usually keep the slope of the needle up when tail injection.
    2. Make sure there is no bubble in the syringe.
    3. If keep the needle slope in parallel with the outside part of the syringe, it is convenient for the tail injection.