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IC50 in MTT assay - please suggest me something (Nov/23/2006 )

Hi to all,

i am research scholar.and little bit confused. i am going to study the cel proliferation assay by MTT

assay. the IC50 for the same drug on similar cell line is already published. and this is different form

that of mine. paper is reporting 700 micro molar and mine is 1.2 mM. and this is controversial. now

could someone suggest me what should i do.


and i also want to know the method of calculating the IC50.

your help will be highly appreciated.

-pBS-

QUOTE (pBS @ Nov 23 2006, 10:20 AM)
Hi to all,

i am research scholar.and little bit confused. i am going to study the cel proliferation assay by MTT

assay. the IC50 for the same drug on similar cell line is already published. and this is different form

that of mine. paper is reporting 700 micro molar and mine is 1.2 mM. and this is controversial. now

could someone suggest me what should i do.


and i also want to know the method of calculating the IC50.

your help will be highly appreciated.


there may be different conditions in yours and published results; to compare IC50 you should try identical conditions to what you compare (formulation of drug, incubation, densitiy of cells, culture conditions (medium!), dishes, coats etc...);

are the drugs from the same source? there may also be differences between lots

-The Bearer-

Similar cell line does not mean the same cell line.

So not only can you not expect the same result if the cell line is different but 1.2 mM is not all that far from 700 ┬ÁM. It's not even double. If it were an order of magnitude different then I'd worry, but only if it it were the IDENTICAL cell line.

We have tested the same drugs over numerous prostate cancer cell lines. Some look the same, grow the same, behave the same. But the IC50 values are all different and sometimes significantly.

-Doc_Martin-