So in this way, under the condition of incomplete information in the protein sequence database, biologists can ever analyze the tandem mass spectrometry data. However, de novo sequencing would not be influenced by the error information in protein sequence database. This is the main method of protein identification, which has strong dependence on protein sequence databases. The database search is mainly to match the actual mass spectrometry and protein sequences from the database theoretical cracking map. Mass spectrometry method to identify the proteins divides into two common analysis methods are the database search and de novo sequencing. It is de novo sequencing mass spectrometry which can be applied to protein de novo sequencingand also peptide de novo sequencing. In recent years, based on mass spectrometry, high-throughput proteomics has developed rapidly, the use of tandem mass spectra identification of protein is a basic and important link in its data processing. Take an example here, the virus has a high mutation rate and can be sequenced in the approach of de novo sequencing service instead of re-sequencing. In this way, we can find out a lot of single nucleotide polymorphism loci (SNP), Insertion loss loci (InDel, Insertion Deletion), Structure mutation loci (SV, Structure Variation) and Copy Number Variation (Copy Number Variation, CNV) Variation etc., so that to obtain the genetic characteristics of biological groups. Re-sequencing refers to doing genome sequencing in the case of known species genome, aiming at different individuals within the species or different tissues of an individual, Thus, scientists can find the difference between different individuals or tissue cells at the genome level. The following picture shows protein sequence.ĭifferences between de novo sequencing and re-sequencing Aiming at the different length of genome sequencing DNA fragments and its library, and then biologists use bioinformatics methods for matching, the assembly and annotation, finally obtain the complete genome sequences of map. Genome de novo sequencing refers to the sequence of a species' genome which is unknown or without proximal species. At present, de novo sequencing service is widely used to analyze the genome sequence, genetic composition and evolutionary characteristics of unknown species from scratch. A species can be sequenced without any genetic information through this method. The sequence was spliced and assembled by bioinformatics analysis to obtain the genome sequence map of the species. A simple introduction of de novo sequencing

De novo protein sequence analysis