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Why does medium turn yellow fast during the intensive synthesis of exogenous pro - Is it the by-product of metabolism?Is it lactic acid? (May/02/2010 )

I noticed that in the case of overexpression of exogenous protein in 293T by transfection,the medium will accelerately turn to yellow?
What is the cause that turn medium to yellow or that lower the pH in general?
Is it the by-product of metabolism?Is it lactic acid?
Will the intensive synthesis of exogenous protein product huge mount of such things?
Cuz after transfection of 3 vectors(25ug each 10cm dish of 293T) in lentiviral package,the medium canít hold on more than 24 after the change of medium 8 hours after transfection before it begin turn to yellow,which prohibit me from collecting more virus,like 48hours after?So can I add some buffer like HEPES to stop it from become yellow so soon?
Well,can you give me some advises?

-AllenChiu-

AllenChiu on May 2 2010, 07:20 AM said:

I noticed that in the case of overexpression of exogenous protein in 293T by transfection,the medium will accelerately turn to yellow?
What is the cause that turn medium to yellow or that lower the pH in general?
Is it the by-product of metabolism?Is it lactic acid?
Will the intensive synthesis of exogenous protein product huge mount of such things?
Cuz after transfection of 3 vectors(25ug each 10cm dish of 293T) in lentiviral package,the medium canít hold on more than 24 after the change of medium 8 hours after transfection before it begin turn to yellow,which prohibit me from collecting more virus,like 48hours after?So can I add some buffer like HEPES to stop it from become yellow so soon?
Well,can you give me some advises?


your transfected cells seems to exhibit accelerated proliferation or general metabolism; increased secretion of lactic acid is a possibility; increasing buffer capacity is posible but you have to check osmolarity if adding buffer components to the cell medium; another possibility is to reduce proliferation factors of your medium; are you culturing with supplements?

-Inmost sun-

Inmost sun on May 2 2010, 06:53 PM said:

AllenChiu on May 2 2010, 07:20 AM said:

I noticed that in the case of overexpression of exogenous protein in 293T by transfection,the medium will accelerately turn to yellow?
What is the cause that turn medium to yellow or that lower the pH in general?
Is it the by-product of metabolism?Is it lactic acid?
Will the intensive synthesis of exogenous protein product huge mount of such things?
Cuz after transfection of 3 vectors(25ug each 10cm dish of 293T) in lentiviral package,the medium canít hold on more than 24 after the change of medium 8 hours after transfection before it begin turn to yellow,which prohibit me from collecting more virus,like 48hours after?So can I add some buffer like HEPES to stop it from become yellow so soon?
Well,can you give me some advises?


your transfected cells seems to exhibit accelerated proliferation or general metabolism; increased secretion of lactic acid is a possibility; increasing buffer capacity is posible but you have to check osmolarity if adding buffer components to the cell medium; another possibility is to reduce proliferation factors of your medium; are you culturing with supplements?

Thanks very much!

-AllenChiu-