Conclusion

The removal of DNA from cell culture broths and lysates may be required to accomplish the CBER-recommended concentration of DNA impurity of <100 pg/dose in therapeutic dosage forms. In many purification processes, it is desirable to remove impurities as early as possible from the process. 3M Purification's Zeta Plus depth filter medium has been extensively used in upstream processes to clarify cell culture broths and cell lysates and serves as an effective means to reduce contaminating levels of DNA. The positive surface charge has been shown to be effective in reducing DNA by 1–2 logs.