Similarity Based Methods for Gene Finding

• Comparison to EST databases.
• Comparison of genomic sequence translated, to protein database.
• Spliced alignment.
• Comparison of translated genomic sequence to translated genome/cDNA sequence.
• Comparison of genomic sequence with homologous genomic sequence from close organisms.

All this methods can give a good clue for existence of a gene but they rely on the accuracy of the database they use. Similarity based methods can identify only 50% of human genes. They cannot identify genes unique to human, nor genes whose protein is unavailable.