7 replies to this topic

[floz]

Hi, does anyone know what is it in the waste that the cells produce that turns the media acidic (yellow)?

Many thanks!

[pito]

I think you need to give more specifics to get an answer to your question.

What media? What cells? ...

[arera]

Normally mammalian cells will turn yellow with time if not treated properly and get contaminated...

[AllenChiu]

have you figure out the reason?and do you have any way to delay it from being yellow?

[tongck]

the metabolic waste of cells or dead cell is acidic and thus change the color of the media

[rhombus]

tongck, on Jun 3 2010, 06:26 AM, said:

the metabolic waste of cells or dead cell is acidic and thus change the color of the media

Dead Cells will not turn the media colour yellow as they are not actively metabolising products in the media. Normally if the cells are dead, the media colour turns more alkaline i.e. a tinge of purple.
Actively growing cells will produce acid by-products, such as lactic acid, released into the media, thus turning it yellow.

Other causes of media colour change:

Bacterial contamination
Wrong CO2 Concentration in the Incubator

Contamination by Mycoplasma DO NOT affect the media....cannot be seen under the microscope.....and is therefore impossible to see. That is why regular testing for mycoplasma contamination is essential

Kindest regards

Uncle Rhombus

[AllenChiu]

rhombus, on Jun 3 2010, 07:05 PM, said:

tongck, on Jun 3 2010, 06:26 AM, said:

the metabolic waste of cells or dead cell is acidic and thus change the color of the media

Dead Cells will not turn the media colour yellow as they are not actively metabolising products in the media. Normally if the cells are dead, the media colour turns more alkaline i.e. a tinge of purple.
Actively growing cells will produce acid by-products, such as lactic acid, released into the media, thus turning it yellow.

Other causes of media colour change:

Bacterial contamination
Wrong CO2 Concentration in the Incubator

Contamination by Mycoplasma DO NOT affect the media....cannot be seen under the microscope.....and is therefore impossible to see. That is why regular testing for mycoplasma contamination is essential

Kindest regards

Uncle Rhombus

as you mentioned"Wrong CO2 Concentration in the Incubator"
so if I was supposed to add 1.8g NaHCO3 but I actually added 3.7g,what is the consequence?
And what is the theory and calculation behind this?

[rhombus]

AllenChiu, on Jun 3 2010, 12:26 PM, said:

rhombus, on Jun 3 2010, 07:05 PM, said:

tongck, on Jun 3 2010, 06:26 AM, said:

the metabolic waste of cells or dead cell is acidic and thus change the color of the media

Dead Cells will not turn the media colour yellow as they are not actively metabolising products in the media. Normally if the cells are dead, the media colour turns more alkaline i.e. a tinge of purple.
Actively growing cells will produce acid by-products, such as lactic acid, released into the media, thus turning it yellow.

Other causes of media colour change:

Bacterial contamination
Wrong CO2 Concentration in the Incubator

Contamination by Mycoplasma DO NOT affect the media....cannot be seen under the microscope.....and is therefore impossible to see. That is why regular testing for mycoplasma contamination is essential

Kindest regards

Uncle Rhombus

as you mentioned"Wrong CO2 Concentration in the Incubator"
so if I was supposed to add 1.8g NaHCO3 but I actually added 3.7g,what is the consequence?
And what is the theory and calculation behind this?

Dear AllenChiu,

Please read attached link.....technical data sheet for DMEM:

http://tools.invitro...TL-HL050602.pdf

It is very important to have the:

Right amount of sodium Bicarbonate WITH the correct concentration of CO2 in the Incubator. The incubator should be FYRITED on a regular basis. Variations in these parameters WILL DEFINETELY effect experimental results.

Kindest regards

Uncle Rhombus