As sample material for the molecular genetic detection of hereditary diseases, for parentage analysis as well as for determining coat colours and blood types, EDTA whole blood samples (approx. 1 ml) are suitable. Alternatively, in dogs and cats, buccal swabs, so-called cheek swabs, can be used. For each animal, 2 buccal swabs (without transport medium) should be supplied. To create DNA profiles and parentage reports in dogs and cats, we recommend to always send in a blood sample. For all genetic testing in horses, it is sufficient to supply about 20 hair roots from mane or tail for DNA isolation.
EDTA blood is the most suitable sample material. It is absolutely essential to use EDTA as anticoagulant. Lithium heparin or citrate are unsuitable as anticoagulants, as they may inhibit the subsequent PCR. In very rare cases, haemolysis induced by transport or extreme stress during sample collection might lead to the situation that no result can be obtained. However, the percentage of blood samples which cannot be evaluated is extremely low, being < 1%.
Buccal swabs, often incorrectly called saliva samples, are very suitable sample materials for genetic testing in dogs and cats, as long as the sampling procedure is performed correctly observing the following rules:
- The animal should not have eaten anything for about 1 hour prior to the sample collection. It should be ensured that puppies and kittens have not been nursed for a minimum of 2 hours, as otherwise maternal cells might skew the results.
- When taking the sample, it should be scrubbed strongly at the inside of the cheek to make sure that enough cells of the oral mucosa and thus genetic material is attached to the swab. Genetic testing can only be conducted if enough genetic material adheres to the swab. Generally, saliva alone is not sufficient. However, there should not be any blood on the swabs!
- In order to prevent the growth of bacteria and mould, the swabs should be dried for about 2 – 4 hours after collecting the sample. This is best done by keeping the test tubes a little open for a while.
As there is considerably less cell material available from mucosal swabs compared to blood samples, it is not always possible to isolate enough DNA from buccal swabs for a genetic test. This applies to about 5% of the submitted buccal swabs. We recommend sending two buccal samples per animal, so there is more material available for testing.
For horses, hair roots can be used to perform genetic examinations. To do so, about 20 pulled mane or tail hairs are needed. If samples are taken from various animals, hands must be cleaned thoroughly after each sampling – even a single hair of a different animal can skew the result.
Hairs can, for instance, be shipped in little plastic bags or in envelopes. It is, however, absolutely necessary to make sure that the hairs are put in a closed envelope, separate from the submission form, when sent in.
There should not be any blood samples sent in for cattle from multiple births because of a possible blood chimerism, but if the test allows it, hair roots, sperm or tissue samples can be used. One exception to this is the freemartin test, for which a blood sample is mandatory.
If you wish to supply sample materials different from those listed above for performing genetic tests, please contact us before sending the samples.