GENE REPORTER ASSAY, KIT, AND CELLS FOR DETERMINING THE PRESENCE AND/OR THE LEVEL OF A MOLECULE THAT ACTIVATES SIGNAL TRANSDUCTION ACTIVITY OF A CELL SURFACE PROTEIN
The present invention relates to a commercializable cell and to a gene reporter assay method and a kit which use this cell to determine the presence and/or the level of a molecule that activates signal transduction activity of a cell surface protein. This cell is treated in such a manner that it will have a sufficiently long shelf life for its intended purpose, whereupon at the end of its useful shelf life or at the end of its use, i.e., in an assay, the cell undergoes cellular death.
1 . A method for commercializing a cell line having a desired biological activity, comprising:
treating the cell line such that the cell line will maintain the desired biological activity for no more than about 30 days at a temperature above freezing, but cannot be propagated or maintained thereafter;
freezing the treated cell line at a temperature and under conditions such that it will resume the required biological activity after thawing; and
selling or distributing the frozen treated cell line whereby said cells will be available for a limited time but cannot be propagated and maintained indefinitely for multiple uses.
2 . A method in accordance with claim 1 , wherein said treating step comprises treating the cell line such that the cell line will maintain the desired biological activity for at least about 8 hours, but no more than about 30 days at a temperature above freezing.
3 . A method in accordance with claim 2 , further comprising the step of suspending the treated cell line in a solution containing a cryopreservative before said freezing step.
4 . A method in accordance with claim 3 , wherein the cryopreservative is a combination of DMSO and glycerol and the solution contains 2.5% DMSO and 10% glycerol.
5 . A method in accordance with claim 3 , wherein the solution comprises RPMI medium and 40% fetal bovine serum.
6 . A method in accordance with claim 2 , wherein said treating step treats the cell line with an agent, which is anti-mitotic and pro-apoptotic, in a sufficient amount and for a sufficient time such that the cell line will maintain the desired biological activity for at least about 8 hours, but will lose said signal transduction activity and undergo cellular death in no more than about 30 days at a temperature above freezing.
7 . A method in accordance with claim 6 , wherein the anti-mitotic and pro-apoptotic agent is vinblastine.
8 . A method in accordance with claim 6 , wherein the anti-mitotic and pro-apoptotic agent is 5-fluorouracil.
9 . A method in accordance with claim 1 , wherein, in said freezing step, the temperature is about −80° C.