Animal services

The basic strains in OULAC will be bought from a commercial producer who abides by the FELASA (Federation for Laboratory Animal Science Associations) European health monitoring guidelines.

Importing special strains

• Special strains may be brought to OULAC both from commercial producers as well as from the researchers’ co-operation partners and other research establishments
• Find out which strain is required and who produces the strain in question. You can ask for assistance from OULAC when needed
• Deliver a health monitoring certificate for the animals (in accordance with FELASA) to the OULAC veterinarian.
• Negotiate a suitable time for delivery with the OULAC research technician
• Notify the OULAC research technician of the exact information on the animal strain, number, sex and age, as well as the preferred time of delivery
• Make sure that your project (animal experiment) licence, or notification of use, are valid
• GM animals must always be reported in the OULAC GM register in connection with the delivery
• If the animals (mice) are cleaned for the barrier, please also contact Biocenter personnel
• The establishment delivering the order will usually see to the details of the cargo and import licences

When using laboratory animals, animal health, well-being and microbiological cleanliness are emphasized. For both health-related and scientific reasons, more and more laboratory animal establishments clean their animal units of harmful microbes. For this reason, the establishments require specific information on the microbiological and health status of the arriving animals.

When the research requires a certain species or strain that OULAC does not maintain, the researcher should first contact the OULAC veterinarian (Sakari Laaksonen) or director (Hanna-Marja Voipio), and premises for importing the animal will be clarified. The microbiological and health status of the animals being imported should first be clarified. A health monitoring certificate shall be requested from the animal supplier, establishment or researcher, based on which the OULAC veterinarian makes the decision on receiving the animals and possible other procedures. In addition, the time for receiving the animals and starting the experiment at OULAC shall be agreed upon with the research technician of the research unit.

Usually the sending establishment is responsible for the animal transportation plan and licences related to the transportation. Delivering the animals must always be performed in co-operation with OULAC such that the delivery schedule is clear early on and the animals will be appropriately received. Animals delivered from elsewhere shall be placed in the research unit, isolator or quarantine unit.

Domestic deliveries are usually dealt with through the JetPak delivery company. The process is expedited if the payer of the delivery has a JetPak customer number.

Please submit the following information to OULAC for an animal delivery:

• The address, contact person and phone number of the recipient
• Specific information about the animals to be sent and, when needed, a completed KEKS animal order form, unless the order pertains to the researcher’s own mice
• Preferred time of delivery
• The address information of the payer or JetPak customer number

Please submit the following information to OULAC for an animal delivery:

• The name, address and phone number of the recipient
• The contact information of the payer and authorisation to use the World Courier services
• Specific information about the animals to be delivered and, when needed, a completed OULAC animal order form, unless the order pertains to the researcher’s own mice
• Preferred time of delivery
• World Courier customer number (if available)

The arrangements will take 1-2 weeks depending on the licence procedures. Signatures of the designated veterinarian are required, and the veterinarian inspects the delivered animals. For deliveries to certain countries, an inspection by an official veterinarian (municipal veterinary officer) is required.

When transporting mice, autoclavable Taconic transportation boxes will be used and the extra cost associated with this will be charged to the customer

Internal price = price for invoices billed within Oulu University
External price = price for invoices billed outside Oulu University
VAT and administrative costs will be added to internal invoices paid through external sources
VAT and administrative costs will be added to external prices

Prices listed below do not include the VAT or administrative costs

MICE, OWN BREEDING

RATS, OWN BREEDING
OULAC does not breed rats at the moment. Rats can be purchased from external vendors according to agreement.

ANIMALS PURCHASED FROM EXTERNAL VENDORS

The price of the animals, delivery costs and administrative costs will be charged.

ANIMAL CARE PRICE PER DAY

Other services will be agreed separately.

The recommendable way to catch mice from the cage is to use a tunnel or by making a cup with your hands. If using the tunnel, place it next to the cage wall and gently guide the mouse into it. It the tunnel is not nexxt to the wall, mice easily swerve aside, and it is much more difficult to catch them. Close the end of the tunnel with your hand to prevent the mouse from coming out. You can then move the tunnel for example into another cage or onto the cage lid for handling. According to studies, this way of catching the mouse causes less anxiety.

Another possibility is to make a cup: place your hands on both sides of the mouse or mice inside the cage, slide them together under the mouse/mice, and pick them up. A mouse that are unused to this procedure may try to escape, in which case it is good to close your hands around the mouse and wait for up to half a minute and then open the cup again The mouse may escape then but with repeated daily training sessions of 1-2 minutes it will get more accustomed for the handling method. This method is not necessarily successful without prior habituation of the mice.

Another way to pick up the mouse is to hold it by the neck skin with fingers or rubber-tipped forceps.

For performing other procedures, the mouse may be placed on a surface which it can grip (e.g. on the lid of the cage, across the metal wires). Holding on to the root of the tail with a slight pull backwards will make the mouse grab onto the surface with its front feet and hold still. If the mouse is calm, it may be directly grabbed on the neck skin right behind the ears. All the loose skin must fit between the thumb and index finger so that the mouse cannot turn its head. The mouse can be picked up and the root of the tail should then be pressed against the palm with the ring finger or little finger of the hand holding it. Now the mouse is in a secure hold, and the other hand is free, for e.g. injections or gavage.

If the mouse is restless or aggressive, it is better to first press your thumb and index finger on its rear end and press it lightly against the surface, and then slide the fingers over the back to behind the ears to get hold of the neck skin.

You must not be afraid to use sufficiently assertive holds – yet not squeezing too much! – and to act quickly but without haste. Otherwise it will be difficult to catch and control the struggling mouse.

Rats can be caught in different ways depending on their state of calmness and how used to being handled they are, as well as the skill and experience of the person handling it. Alternative holds:

• Grab tightly around the chest so that your thumb is behind the other front leg, while the other leg remains between your index finger and middle finger, and your index finger is under the lower jaw preventing the rat from biting.

• Grab the rat at the back so that its neck is between your index finger and middle finger, and your thumb, ring finger, and little finger are around the chest behind the front legs.

• Collect the rat’s loose neck and back skin together in your hand with a firm grip.

• Grab the rat by the root of the tail and pick it up on your arm or on a surface, after which it may be grabbed in one of the ways described above.

If the rat is not used to being handled or it is otherwise aggressive, there is reason to be careful and to rather catch it at the root of the tail. When necessary, a strongly struggling animal may be wrapped in a cloth. The rat can be picked up by the tail only for a moment, and it is not a recommendable approach for constant use.

The animals are marked either by notching the ears, tattooing them or with a marker pen on the tail. The scheme is usually different in different laboratory animal centres. Therefore the scheme must be sent alongside with the animals to the associates of the LAC. An ink mark must be intensified almost daily, but the notches and tattoos are permanent.

Mouse

It is possible to inject under the skin when holding the animal in a neck-skin hold: either from the front at the base of the skin fold between the thumb and index finger (be careful not to stick your fingers), or beneath the lateral skin in front of the hind leg. The needle must be introduced very obliquely beneath the lateral skin, and in order to ensure the correct location of the needle tip you can lift the skin slightly with a sideways movement of the needle before injection.

A mouse placed on a surface may also be injected above the pelvis. The mouse should be pulled slightly backwards by the tail so that it will remain still. The tail should be held with the other fingers, while thumb and index finger are used to lift the skin on the pelvis. With the other hand, the needle will then be introduced under the skin fold. This technique requires some more practice and it may be difficult especially if the mouse puts up a lot of resistance.

When the injected substance enters the correct location, there is no resistance in the plunger, and the skin may exhibit a bump depending on the point and amount of the injection.

Rat

Usually a rat is injected beneath the neck or back skin, but it is possible to inject also beneath the lateral or abdominal skin. Injecting a non-sedated rat is easiest if an assistant is holding the rat. The skin must be collected and lifted into a ”tent” and the needle inserted in the “pocket” of the tent at a 20–30° angle. Instead of pushing the needle, you can also pull the skin over the tip of the needle.

It is not recommended to give mice intramuscular injections due to the small size of their muscles, unless it is necessary for research-related reasons.

IM injections are not recommended for rats either, but their muscles are bigger, and if there is a special need for an intramuscular injection, the front thigh muscles can be used (Musculus quadriceps femoris). At the back of the thigh, there is a risk of hitting large vessels or the sciatic nerve. An assistant holds the rat, and the injector holds the thigh muscle with one hand between the thumb and index finger. Before the injection, you should pull slightly on the plunger to make sure that the needle is not inside a vein.

An i.p. injection is made into the right lower quarter of the abdominal cavity. It has been recommended in related literature that the animal be kept head downwards, in which case the organs will be pressed more cranially in the abdominal cavity, ”out of the way”. In practice this does not matter much, as long as the procedure is performed correctly. The needle should be injected from the caudal direction, at a slight angle to the abdominal wall, with a quick and firm movement, but only so far that the tip just barely pierces the abdominal wall. Before the injection you should slightly pull on the plunger: if any fluid enters the syringe, you must inject again with a clean needle and syringe.

Regardless of how skilfully the procedure is done, i.p. injections have a certain risk of failure. Therefore other injection routes are recommended, unless there is a specific need to inject into the abdominal cavity.

An i.d. injection is not recommended unless it is necessary for research-related reasons. Intradermal injections can be done on the back or neck or beneath the abdomen. The animal must be under anaesthesia for the injection. The injection area should be shaved. The needle must be very thin and the amount of liquid small. Pull the skin tight with your other hand, and introduce the needle at a very slight angle right beneath the surface layer of the skin. You can feel clear resistance both when inserting the needle and injecting, and a hard bump will appear at the point of the injection. The needle should be pushed some way inside the skin before injecting, and the puncture point pressed with a finger when taking out the needle, to prevent leaking out of the fluid.

The most common place for an i.v. injection is the lateral tail vein. The injection is difficult especially in mice due to the small size of the vein, and this technique requires practice. Warming the tail or the whole animal dilates the tail veins and significantly facilitates the procedure. Good lighting is important. Injecting an awake animal requires an immobilisation device.

The tail is pulled straight so that it is crossways on the index finger, and the thumb presses the tip of the tail behind the index finger. The tail may also be on the edge of a table. The needle should be held parallel to the tail and inserted into the vein at the exact point where the tail starts to bend downwards. The needle bevel should be pointed upwards. The needle is inserted 2-4 mm inside the vein. If the needle is correctly placed inside the vain, no resistance can be felt in the plunger when injecting and you can see through the skin how the injected substance advances in the vein. After the injection is finished, the normal colour of the vein returns when the blood circulates again. You must press your finger on the point of injection when pulling out the needle, and for a moment afterwards, to prevent bleeding.

Other possible IV injection points are the dorsal metatarsal vein (on the dorsal side of the tarsus), the jugular, femoral, sublingual and penile vein.

For the gavage procedure, you should grab the mouse into a firm neck-tail-hold so that the head in particular is as immobile as possible. Optimally the neck would be straight so that the mouth, pharynx and oesophagus form a straight line, but gavage can be done also if neck is not quite straight. Reaching the correct position can be facilitated if the neck-hold is made with your thumb and middle finger, and the index finger is used to turn the head up from the crown skin.

The mouse should be held in an upright position. The ballpoint probe is carefully inserted into the mouth, and the tip advanced along the palate to the back of the mouth. At this point the probe should be in a parallel line with the oesophagus. The probe must not be pushed down the pharynx with force! When the probe is correctly placed, it will go down easily when the mouse swallows. If the mouse is upright, gravity is enough to advance the probe into the stomach, without any pushing.

A rat should be held around the thorax so that the thumb or the index finger can be used to press the lower jaw, or alternatively the neck and back skin. The probe is inserted into the mouth between the teeth and across the tongue into the pharynx.

Dipping the probe in sugar water right before the oral gavage will facilitate and accelerate the procedure. The animal will resist less and swallow the probe more easily when it tastes sweet.

Possible complications are gavage into the lungs, tearing the oesophagus, and damage to the pharynx. No unnecessary force must be used in the procedure. The animal should be allowed to swallow the probe without forcing it down. A probe of an appropriate size will easily be swallowed up to the base, the tip all the way down to the stomach; in the trachea the probe will not travel as far. When the probe travels through the trachea, your fingers may feel a “vibration” caused by the tracheal rings. If the probe does not travel easily deep enough or the animal starts to cough, gag or otherwise resist once the tip has passed the pharynx, the probe must be pulled out. After a successful gavage the animal will behave normally.

Genetically modified mice are produced and strains are maintained in the mouse barrier unit. GM strains are usually created by research groups and are in their possession. In addition to GM mice, there are also gene modified rat strains that are maintained at the research unit. GM animals can also be purchased for research from outside producers.

Valid facility and project licences are required for creating and maintaining a new GM strain and conducting research with. KEKS has an operating licence issued by the Board for Gene Technology for class 1 contained use of GM animals. The licence requires that all information pertaining to GM strains be kept in the GM register maintained by KEKS.

Maintaining animals treated with viral vectors (e.g. adeno- or lentiviruses), or conducting experiments with them, is possible in KEKS with special arrangements. There are no designated areas for manufacturing viral vectors or otherwise processing them in KEKS; instead, the research departments themselves are responsible for these premises and their GMO licences. More information on GMO licences and classification is available at the website of the Board for Gene Technology.

Basic inbred strains and outbred stocks as well as GM strains are bred and maintained in the mouse barrier. The mice are SPF (specific pathogen free) animals, free of certain species specific pathogenic microbes and parasites. Further information can be found on the pages Mouse barrier and Environmental conditions and care of the animals.

GM animals are produced by the Biocenter Oulu Transgenic Core Facility.
Link to Biocenter services:
https://www.oulu.fi/en/university/faculties-and-units/biocenter-oulu/transgenic-and-tissue-phenotyping-core-facility

After embryo transfer, the KEKS personnel is responsible for the breeding and maintenance of the GM mice.
Services offered:

• Hormone injections for embryo donors and plugging of the recipients as related to producing new strains
• The production and maintenance of GM mice in accordance with researcher instructions
• Time mating and plugging
• Taking DNA samples and delivering the samples to the researchers
• Euthanizing animals
• Delivering mice to researchers based on written orders
• Experimental procedures in accordance with a separate agreement, such as special feed, taking blood samples or other samples
• Keeping records in LabAnimals Pro animal data system

• The breeding orders are done in LabAnimals Pro.
• Breeding and plugging requests should be done 2-3 days before due to the work arrangements.
• The male must be at least 6-7 weeks old and the female 8 weeks old. Animals younger than this shall be used for breeding only in exceptional circumstances. It must also be kept in mind that initiating breeding with mice over six months old may fail. Females over one year old must not be bred.
• When the pups are 14 days of age, they will be ear marked, a DNA sample is taken and they will be appointed a sequential DNA number.
• The pups are weaned from the mother at the age of 21 days. If the pups are small in size, they may remain with the mother until the age of approximately 25–28 days.

New gene modified mouse strains

The University of Oulu Biocenter prepares gene modified strains of mice as a service. The Biocenter Oulu has a project licence for these operations that includes the procedures for producing the first pups of a new strain. GM mice are born in the mice barrier, and the strains are maintained within the barrier.

Before the new strain is produced

• The researcher must apply a project licence for the research
• A GM register notification of the new strain must be submitted to the OULAC GM register

When an existing GM animal strain is intended for use in an animal experiment, a project licence must be applied for at the Animal Experiment Board (Hankelupalautakunta, ELLA).

Crossing existing GM strains

• If neither strain that will be crossed have problems with wellbeing, the researcher submits an internal licence application to OULAC via LabAnimals Pro.
• If one or both strains have characteristics that are harmful in terms of the animal wellbeing, a project licence must be applied for at ELLA.
• If there is suspicion that the new hybrid animal has problems in terms of wellbeing, a project licence must be applied for at ELLA.
• A GM register notification on GM cross-breeding must be submitted to the OULAC GM register.

Maintaining a GM strain

• When gene manipulation does not cause harm to the animal wellbeing, an internal licence is sufficient for maintaining and breeding the strain.
• If gene manipulation does or will compromise animal wellbeing, even maintaining the GM strain requires a project licence.
• In the event that, contrary to predictions, characteristics that compromise animal wellbeing later appear, a project licence must be applied for retroactively.
• The licence guidelines for gene modified animal strains are available on the ELLA website.

Samples for DNA analysis are usually taken when the animal is marked by ear notching. In such cases the main purpose of the notching is the identification of the animal which does not require the project licence. The resampling as well as a sample of the tail require a valid project licence.

The samples should be taken from pups at the age of 14 days. In connection with the sample, the mice are numbered according to the ear number chart used in OULAC.

After analysing the samples, the researcher marks the results for the pups in LabAnimals Pro. It is advisable to do the euthanasia requests at the same time.

The resampling requests for DNA analysis are made in LabAnimals Pro.