Genetic modifications

The intended (and unintended, focusing on genes of concern) genetic modifications introduced in the genome in the laboratory must be verified by sequencing. Today, whole genome sequencing (WGS) is a cost-effective approach to get a full view on all changes in a genome. The genome of the modified organism is usually compared to that of the parental or recipient strain, and in many cases that is already present and available from genome databases.

Biosafe has handled hundreds of modified organisms in-house. We can guide you through selection of appropriate sequencing method for each case and we provide you with a comprehensive report to your genetically modified strain. If the report is to be used to support an application, we will make sure that requirements are fulfilled, and you receive all necessary files in the format required by the authority.

Our experts can also consult on safety aspects of genetic modifications if you are developing a strain and wondering what is acceptable and what should be avoided.

Allergenicity of protein sequences

One key aspect in the safety assessment of enzymes and other proteins is the potential allergenicity. The assessment is a stepwise process, in which bioinformatic analysis is usually the first screening step.

The DNA sequence from which the protein sequence can be inferred, or the actual protein sequence, will be used for the analysis. Several databases are available, which are built based on different principles. Some of them are very stringent in the inclusions, whereas others include proteins based on protein similarity without any real evidence for allergenicity. Some of the databases include proteins, which can be used for the assessment of the potential contribution to celiac disease.

A routine, internationally accepted approach is to run a sliding window search of 80 amino acids through the protein and look for any window having 35 % or higher identity. It is also possible to predict all proteins from the whole genome sequence of a microorganism and make an allergen database search.

Biosafe Ltd uses several databases, compares the results and carefully assesses the outcome.