Bac-Off®

Introduction

Bac-Off^® Tonic for antibiotic treatment of media.

This product was developed to address the problem of unpredictable, inevitable bacteria in cell culture. Cells have, as a natural and normal part of their constitutive programming, the ability to enclose bacteria adherent to their lumenal surface in membrane, and sink them into the cytoplasm. The bacteria, while in these vacuoles do not divide, except if already triggered into the cell cycle, and the resulting doublets do not divide (at least for times on the scale of hours). If the bugs are released, they proliferate briskly. At high multiplicities, cells containing bac-vacuoles are adversely affected, exhibit toxicity and measurable loss of specific activity. The eventual release of even a single viable bacteria from sequestration has predictable and dismal consequences. This product is formulated at MIC to inhibit the growth of most bacterial agents and control contamination in cell culture, without harming the cells.  

Bac-Off^® is intended to provide practical relief to the scientist by exposing the bacteria to effective oblivion from the point of view of the experiment by placing it, once released, in a medium environment containing the adduced MIC of a quinolone antibiotic, acting to interfere with the chromosomal breakage-reunion reaction of bacterial gyrase and human topoisomerase II. Bacterial replication is coupled with and absolutely dependant on chromosomal replication, with as many as several waves of chromosomal replication present in log cultures. In the presence of Bac-Off^® at MIC dosage, bugs are unable to relax replication fork driven supercoiling and are kicked into a prolonged G2 shunt (which could eventually, be fatal). As a practical matter, bacteria released into the medium will be washed away during routine feeding operations.

Dosage of Bac-Off^® was established by identifying the MIC for the bug and the toxicity dosage for human microvascular cells. Nearly twenty-five individual isolates of ACBRI Primary Human Microvascular cells have been probed to date. Results are emerging that indicate that the effective MIC is 2µg/mL (mcg/mL in the parlance of the clinical lab) and that visible toxicity is not encountered until one is north of ~10µg/mL.

Available Formats

Comes in 4mL (4Z0-643) and 10mL sizes. (4Z0-644).

Use

Cells are at their most vulnerable when in recovery from thawing or passage. Add 1mL of Bac-Off^® to each 500mL of media. Feed culture, as usual. If you aliquot and freeze your medium, add Bac-Off^® before dividing and freezing media.

Handling and Storage

Store Bac-Off^® at -20°C until ready to use.  If an entire 500 mL unit of CSC media will not be used within 30 days, activate the medium with growth supplement and Bac-Off then aliquot and freeze in smaller units which will be used within 30 days (store at +4 - 8°C)

CSC media and reagents are Sterile, made with WFI and all components are cGMP and ISO Compliant.

Bac-Off® is stable for at least six months at refrigerator temperatures, and may be frozen (<-20C) one time without loss of activity. No special precautions are necessary for disposal of Bac-Off® solutions at working or double strength.