|Fig. 2 again indicates
the amount of female DNA (FDNA) contamination necessary to alter a
male DNA (MDNA) sexing result. A false result was not obtained until
the contamination ratio was greater than 8:1 or the amount of FDNA
present was greater than 2ng. A contamination level of 16:1 or 1ng
FDNA did not effect the outcome of the final results. It requires
approximately 300 nucleated cells to generate 1ng of genomic DNA.
Thus, using standard ABI DNA sexing protocols, it would take more
than 1200 female cells to generate the amount of DNA necessary to
alter the result of a MDNA sexing sample.
Note: False Result* This result was
not clear and would be considered incomplete and rerun. If a stronger
signal was not achieved, a new sample would be requested and run
at no extra charge.
Both experiments suggested that contamination
can play an enormous role in the final outcome of an assay. However,
these examples also indicate that the level of contamination required
in order to alter a DNA sexing result is relatively high. These
and other findings strongly suggest that having male and female
specimens in close proximity before and during sample collection
will not in any way compromise the accuracy of the final results.
Remember, these finding are based
on Avian Biotech's assays. DNA sexing assays from other labs could
be more sensitive thus making them more susceptible to contamination
errors than ours. Always be sure to use good basic hygiene when
collecting samples. The accuracy of each assay begins with proper
sample collection techniques.
results of females sample contaminated with male DNA
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