medium for mammalian cells

[summer]

what is the difference between serum medium and complete medium?

thanks.

[mith]

I know the complete medium has all the necessary minerals and amino acids but I haven't heard of the serum medium. I'm guessing it doesn't have everything.

[adidasty]

yeah see above. complete medium provies culture with amino acids, essential ions and minerals, and certain coenzymes, but serum medium....im not sure

[DevGrp]

Might you mean complete and serum FREE media?


Complete media is a complex, undefined mix of things usually containing 5-20% serum (often fetal bovine serum -FBS). Cells grow much better when serum is present as it contains a mixture of proteins / hormones / growth factors etc (you can also get heat inactivated serum in which all the proteins have been denatured).

The problem with this is that each batch of serum is different, so people often test a series of batches and then reserve stocks of the best for them. It can also be a problem not knowing the exact makeup of the media. For example we worked on hormones and the levels of estrogen / progesterone / unknow factors etc in the serum was probably quite variable.

one solution to this is to use serum free media. This is a full defined mix of all the things a cell needs to grow. It can include frowth factors / hormones as well as the usual salts, carbon and nitrogen sources etc. This has two disadvantages, the first is cost. adding a blend of purified growth factors to a media is much more expensive than just chucking in some serum. The second is that you need to optimise the media to each type of cell.

hope that was your question?

[summer]

Might you mean complete and serum FREE media?

Yeah, it seems that way.

The problem with this is that each batch of serum is different, so people often test a series of batches and then reserve stocks of the best for them.

Do you mean within a serum type there may be variation in proportions of the ingredients or do you mean that different serum types may have variation in proportions of the ingredients? What is batch in this context?

thanks for your reply.

[DevGrp]

Within a serum type

We would buy one particular catalogue number of serum. Every couple of years the company (Invitrogen) would send us some small bottles of their new batches of this particular serum, we would then test them to see if our cells grew and then select a specific batch and reserve enough for the next few years.

So it's variation between batches of the same product.

I'll have to admit, the last time we tested they all acted the same so Invitrogen might have got better at standardising their serum

[summer]

Thank you very much for your great answers!

Do you have a protocol for testing each serum batch?

[DevGrp]

the answer is nothing fancy

just plated the cells at the same density in media containing the different serums and after a few days (and well before confluence) assess growth

MTT (the original)/ WST-1 (Roche's soluble MTT) / MTS (Promega's soluble MTT) / heamocytometer count / 3Hthymidine are all ways we have done this or even just look under the microscope and do a guesstimate.

It is also important to look at the cells and check that the morphology is what you expect as fast growth is not the only factor.

We then tried to complete sets of experiments using the same batch of serum. This at least removes one variable

[summer]

Thank you.