GD Animal Health is able to apply conventional culturing techniques, and develops and uses ultramodern techniques and innovations for virological testing. That enables us to offer a wide variety of tests and studies for cultivating, isolating and identifying viruses, and for demonstrating virus antibodies (VNT). For these services, GD Animal Health uses several techniques, including PCR, virus isolation, virus neutralisation tests, ELISA (both antigen and antibody ELISA), IPMA and agglutination techniques.
GD Animal Health innovates in efficiency and quality
GD Animal Health is continuously searching for techniques that make virus testing quicker, cheaper and more efficient. We do this by ‘pooling’ blood samples, for example. Testing is based on a (large) number of blood samples while the price and reliability of the results are the same as that of testing one blood sample. When a signal is detected in a pooled sample, all samples from the pool are tested individually. This is particularly cost-efficient for large batches and for when the percentage of positive samples is low. For free-certification of livestock farms, for instance, but also for comprehensive studies or farm-screening projects. The PCRs for BVD virus in cattle and PRRS virus in swine are tests for which GD Animal Health uses pooling as standard.
Immunological testing counts for a substantial part of all tests carried out by the GD Animal Health laboratory. Most tests are carried out automatically by robots, giving a capacity of 15,000 sera a day. For some virus infections, such as IBR and Aujeszky’s disease, GD Animal Health uses ELISAs that can distinguish between antibodies that have developed against vaccine virus or against field virus. This makes a major contribution to control programmes that use vaccination.
PCR (Polymerase Chain Reaction) is a molecular-biological technique that can very specifically demonstrate the presence of a small amount of pathogenic organisms (viruses or bacteria). The principle of the PCR test is based on propagation of a specific genome section (DNA or RNA) in a test sample. Eventually, the reaction results in a large quantity of a DNA fragment with a length and base sequence that are characteristic for the pathogenic organism in question. GD Animal Health routinely uses various PCR tests, in many cases developed in our own R&D lab or in cooperation with other institutes. Real-time PCR technique is another option offered by GD Animal Health. The reaction progress can be observed directly (real-time), and the results are available sooner. There is even less contamination risk compared to conventional PCR. qPCR!
GD Animal Health also offers other advanced molecular-biological typing techniques, such as sequences analyses, restriction analyses, fingerprinting, etc.
Virus isolation and the GD Animal Health virus bank
Virus isolation is an effective and specific method for the detection of viruses in many samples. For routine testing, virus isolation is used less frequently now because this method is rather expensive, and other excellent alternatives are available. Nowadays, ELISA and PCR are the commonly used techniques to demonstrate virus infections. A rather new service in the GD Animal Health package is to identify or to type microorganism variants through sequencing techniques and other fingerprinting techniques. GD Animal Health uses the virus isolation method, e.g. for vaccine efficacy studies and for collecting field strains for our virus bank. Field strains are stored carefully for use in new studies. The conventional culturing of viruses is also very useful for the detection of new viruses or new virus types.