Figure 4.2

PCR products from fixed specimens. Primer sets: lanes 1-3, A/22R and lanes 4-6, A/18p. Lanes 1 and 4 contain products amplified from formalin-fixed S. fuelleborni samples and lanes 2 and 5 contain products amplified from S. suis previously extracted genomic DNA. Starting material from both sources was incubated in GTES (see text and Appendix A1) and genomic DNA extracted using the Nucleon HT extraction kit (see fig. 4.1). Lanes 3 and 6 are positive controls and contain products from fresh C. elegans samples. Comparing lanes 1 and 2 with 3, yield does not appear significantly reduced when short sequences are amplified (~400bp). Full-length products are obtainable from formalin fixed material (lanes 4 and 5, labelled with red arrow). Yield with full-length products is however extremely low (lanes 4 and 5 in comparison with lane 6) and these products could not be cloned.