FELASA Module 10 Practical Exercises

FELASA Module 10: Practical Exercises
 Will cover functions A (Taking part in experiments), B (License holder) and D (Killing
Animals)
 Three exercise sessions of four hours each
 Practical 1: Needles and Syringes and basic handling of rats
 Practical 2: Minor Procedures in Rats
 Practical 3: Handling and minor procedures in mice
 Firstly learn how to use needles syringes and gloves
 Introduction -> Handling toy animals-> Handling live animals-> Anaesthesia->
Procedures-> Euthanasia and necropsy
 Needles come in different sizes (Gauge- G)
 Gauge defines the diameter of the puncture hole
 High gauge is a small needle, smaller gauge is a bigger needle
 Needles are changed after every injection
 Disposable needles start to bend if reused
 Tissue material also gets stuck on needle
 Proper sized syringe needs to be used
 Plunger shouldn’t be pulled more than 2/3 out
 Plunger should be worked up and down before using the needle
 The tip of the needle has a dead space (where compound will stay inside the needle)
 There is also dead space inside the needle
 Need to mix more compound than you need
 Volumes read from the bottom of the rubber compound
 Work as aseptically as possible- either have someone remove needle or put it onto an
aseptic surface then wash hands and change gloves
 Don’t touch the tip of the syringe or connection part of the needle
 Use large needle to withdraw with
 Needle can be left in the vial for this course
 Syringe attached
 Vial flipped
 Plunger mixed to remove air bubbles
 Tip vial over and empty large needle using syringe- this ensures there is excess solution
 Make sure to get the right volume and more for dead space
 Remove needle and put in sharps bin
 Put injection needle on
 Pull plunger down
 Flick syringe to remove small bubbles at the bottom
 Push plunger up till you see the first drop
 Remove excess compound
 Aur bubbles- ideally need to get rid of them all
 Can be lethal if you inject air bubbles
 Try to get rid of any towards the tip as these will be injected
 Inject and aspirate
 Do with dominant hand holding the needle and syringe
 Use both hands to loosen the cap
 Grab syringe with one hand
 Slide needle out of cap
 Penetrate at the place we want to inject
 We withdraw the plunger slightly to aspirate, this makes a vacuum that looks like air
 This makes sure the needle isn’t hitting a small blood vessel
 Aspirate gently so we don’t withdraw blood
 Only safe to inject if there is no blood
 Inject
 Needle and syringes thrown away
 Needle removed using sharps bin

,  If injecting a dangerous compound the cap should also be put in the sharps bin
 Never recap a needle
 If you absolutely have to use one hand to grab syringe, slide needle into the cap, hold
it vertical and lock cap

Rat Procedures
 Handling
 Approach the cage calmly
 Lift rat with one hand around its chest
 Support the hind with the other hand and rest it on your forearm
 Pet rat to calm it before restraint and injection
 Restrain rat with both hands and arm
 Subcutaneous injection
 Make a skin fold with skin and index finger
 Needle inserted into skin below fingers
 Aspirate
 Rat will move a but
 Pet rat afterwards to calm it
 Place rat in separate cage
 Use heating pad to keep rat warm
 Cover cage
 Observe rat during induction phase
 Note time of injection in injection log
 Don’t disturb the rat until expected time of loss of righting reflex is reached
 Check for loss of righting reflex and good muscle relaxation
 Check withdrawal reflexes
 Using forceps pinch between the toes
 If positive wait a few minute to check again
 Moisten the conrnea
 Intravenous injection
 Place the needle parallel to the tail
 Support the tail with a finger underneath
 Aspirate to see blood
 Inject
 Blood sampling by puncture of a tail vein
 Option A
 25G needle used
 Use a tourniquet to dilate the veins
 Make sure the needle is in the right place and aspirate to draw blood
 Option B
 Blood is collected with a hematocrit tube or into an eppendorf
 Option C
 Puncture the dorsal or lateral vein at the tip of the tail
 The blood is collected by dripping or using a hematocrit tube
 Apply pressure to stop the bleeding
 Intradermal injection
 Maximum injection of 0.1ml using 27G needle
 3cmx3cm is shaved on the back
 The bevel of the needle is facing up
 The bevel is placed intradermally and the needle is rotated 90 degrees to make the
bevel point towards the dermal layers
 The injection is performed slowly
 If it is done correctly a firm blister is visible on the skin
 Intraperitoneal injection
 The rat is restrained by cuffing