Internal Control Fails with Non-Human Sample Source

Symptom

The internal control reaction fails to turn yellow when added to nucleic acid isolated from non-human sources (e.g., animal tissue, environmental samples), as the control targets human-specific sequences.

1. 1 Internal control primer set targets human-specific genomic sequences (e.g., RNase P gene) absent in non-human samples
2. 2 Sample is derived from animal, plant, bacterial, or environmental sources lacking human DNA background
3. 3 Mixed samples contain insufficient human material to provide detectable internal control signal

1. 1 Use human-derived nucleic acid input (clinical samples, cell lines) when internal control is required
2. 2 Design and validate custom LAMP primer sets targeting conserved genes in your specific sample organism
3. 3 Spike known amount of human control RNA/DNA into non-human samples as exogenous process control
4. 4 Omit internal control and rely on positive control plus NTC to validate assay performance for non-human samples
5. 5 Use species-appropriate housekeeping gene targets (e.g., 16S rRNA for bacteria, 18S rRNA for fungi)