Technology

Enferplex TB blood test for Mycobacterium bovis

We can currently test blood (serum) samples from alpacas, llamas, deer and goats for TB using the Enferplex TB test. Please contact our partners Sure Farm Ltd if you want samples tested.

A variety of species-specific Enferplex TB serology multiplex tests are available to detect antibodies in serum from animals infected with Mycobacterium bovis. A panel of TB antigens is used in an array format on the surface of a microtitre plate well. These include recombinant proteins, synthetic peptides, and PPD-B. The tests have been used in cattle, sheep, goats, alpacas, deer, badgers, wild boar, and a variety of Zoo species. Samples from other species can also be tested in the same manner. Please contact us for further details about the tests.

PLEASE NOTE: We do not yet have permission to test UK cattle using Enferplex TB. We have requested permission from DEFRA and hope to be able to offer this test in the future.

Multiplex technology

The multiplex serology test is based on standard ELISA principles, except that individual antigens are printed onto the bottom surface of microtitre plate wells in discrete spots to produce antigen arrays, and a chemiluminescence endpoint is used. Individual antigens (crude extracts, recombinant proteins, or peptides) are deposited in small volumes (10 - 50 nl) at specific positions to produce arrays (e.g. 3 x 3, 3 x 4, 4 x 4, 4 x 5, 5 x 5 etc). Following drying, the plates are blocked using conventional ELISA blocking agents. Thereafter, suitably diluted serum, plasma, or milk samples are incubated on the array. After washing, a HRP-labelled anti-IgG conjugate is incubated then washed off. A chemiluminescent substrate is added, which upon contact with HRP gives off light. The light emission is restricted to the spots, and is detected using a specialised reader that measures the intensity of the light. This is converted into arbitrary 'Relative Light Units' by associated software, allowing the results to be presented in a variety of formats as required.

Each antigen spot is individually validated using defined positive and negative reference samples, and has its own cut-off. A 'Blank' spot position where no antigen was printed is used to provide a background value for each sample tested, thus doing away with the need for "Confirmation" tests since it is done as part of the assay.

An Excel Macro allows the results to be normalised to a reference positive control, hence reducing plate to plate variation. Within and between plate variation is less than 10%, and usually around 3 - 5%.

MVD-Enferplex array for detecting antibodies

Please contact us for further details.