Marker Retention service, also known as Plasmid Loss testing service, is offered to determine the percentage of cells in a cell sample that contains a selectable marker such as antibiotic resistant gene. In microbial cell culture process, a bacteria stain may lose its antibiotic resistance due to the loss of its resistant-coding plasmid, an undesirable event in biologics manufacturing.
Test sample will be tested for the presence or absence of the selective marker, such as an antibiotic resistant gene coded in the plasmid in E. Coli. Test sample, positive, and negative cells will be plated to obtain isolated colonies. Results will be reported as the percentage of cells retaining the marker, or percentage of plasmid loss.
A report with the following information will be delivered: images of selective and non-selective growth plates, colony counts, and calculation of percentage of marker retention or plasmid loss.
Genomics & Biological Services
Experienced scientists functioning as project managers or study directors
Independent quality unit assuring regulatory compliance
Methods validated per ICH GLP/GMP guidelines – also research grade testing available
Rigorous sample tracking and handling procedures to prevent mistakes and cross-contamination
Controlled laboratory environment to prevent cross-contamination