Hybridoma TechnologyBioventix sheep monoclonal antibodies (SMAs) are created using similar methods to techniques established in the 1980s to create mouse monoclonal antibodies. The distinctive and key differences are that a sheep hetero-myeloma fusion partner is used to immortalise sheep B cells. The Farnham laboratory developed the sheep fusion partner during the 1990s in order to establish a reliable and reproducible hybridoma technology that generates stable and productive cell lines.SMAs to ProteinsSheep monoclonals - as compared to mouse monoclonals - are almost always of a higher affinity and this can be useful in assays for analytes that are in serum at very low concentrations around10-10 to 10-14 molar.In addition to this phenomenon of high affinity, sheep have been shown to have a much broader range of epitope recognition.This can be evidenced as a wide-ranging recognition of small linear epitopes by pepscan analysis - usually performed with overlapping and biotinylated peptides of 10-20 amino acids.
SMAs to Small MoleculesIn almost all cases evaluated in our Farnham laboratory, SMAs made to small molecules have been of a higher affinity than mouse monoclonals that can be obtained from other third parties. In most assay systems, this translates into increased assay sensitivity and precision, which can lead to technical and commercial advantages. Using ELISA based assay systems, Bioventix can screen for desired cross-reactivity (e.g. in drug testing) or against undesired cross-reactivity (e.g. in clinical immunodiagnostics).Low levels of testosterone as found in women and children cannot typically be measured reliably by immunoassays.The Bioventix SMA to testosterone (Testo3.6A3) has proved successful in immunoassays that are able to give good correlation with reference methods such as ID-GCMS thereby overcoming the deficiencies reported by Taieb et al. 2003 and Moal et al. 2007. High affinity to free testosterone combined with low cross-reactivity with DHEA-S are central to the properties of this SMA.