FBI DNA Collection

FYO THE standard forensic DNA test, such as those used by the FBI and integrated into the CODIS system (beginning in 1990) , would typically indicate the biological sex of the individual. The standard DNA profiling kits used by forensic labs include an Amelogenin marker which indicates the presence or absence of the Y chromosome. A profile showing an XX result indicates a biological female. A profile showing an XY result indicates a biological male. Therefore, when the FBI processed the DNA sample from the person they believed to be Raymond Reddington in 2013, their lab tests would have automatically included an indicator for biological sex (likely male/XY, to match the individual presenting as a man) as a standard part of the profile report. Within the Blacklist universe, the potential for a different biological sex became a plot point, with the in-show explanation suggesting that standard CODIS tests focus on identifying individuals via short tandem repeats (STRs) and don't necessarily trigger an alert for a mismatch in biological sex if it's not the specific parameter being cross-referenced or if a more rigorous, in-depth test isn't specifically requested.

In reality, however, the sex indicator is a standard part of the generated profile.