ý.,,: V. ý ýý . - Nottingham eTheses - University of Nottingham

inhibit growth along the axis upon which they act perpendicularly. Thus when the ice
crystal is held at a temperature, close to its hysteresis temperature the corresponding
increase in the rate of crystal growth produces extensive growth along the axis not
`protected' by the influence of AFPs (Grandum et al, 1999; Barrett, 2001; Jia & Davies.
2002).
4.4 -
Conclusions
To increase the number of culturable isolates which could be screened for AFPs
when in Antarctica, a new protocol was developed based on the SPLAT assay. but
without the disadvantages which made SPLAT analysis in inaccessible field locations
unfavourable. The new assay, the high-throughput AFP protocol (HTAP). was cheaper.
faster, less labour intensive and was able to analyse large numbers of bacterial isolates at
one time. 866 isolates were screened for AFP activity using the HTAP assay, only 187
showed RI activity. One of the drawbacks to using the HTAP assay is that it produces
false positives due to sample colouration. Therefore, all putative positive isolates had to
be re-analysed using the conventional SPLAT assay upon return to England. Only 19 of
the HTAP positive isolates were proved to be positive using the SPLAT assay.
The HTAP assay is an excellent first stage assessment technique for reducing the
number of isolates which have to be assessed using the more accurate, but slower and
more labour intensive, SPLAT assay.
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