Analyse Nutrients and Contaminants in Cell Culture Media with TXRF Spectroscopy
How to use TXRF (Total Reflection X-Ray Fluorescence) spectroscopy to maintain consistent conditions for cell cultures in biopharmaceutical research and production:
- Measure nutrient elements
- Identify contaminants
- Maximise yield of biopharmaceutical products
Control of Cell Culture Media
TXRF spectroscopy can be used to measure the composition of cell culture media in biopharmaceuticals, in order to maintain a constant balance of :
- Amino acids
- Nutrient and trace elements eg P, Zn, Cu, Fe, Se, Mn
This ensures the cells stay healthy and delivers the maximum yield of biopharmaceutical product.
Using the Bruker S4 TStar, this technique can be used in production, research and quality control to measure nutrient elements and identify contaminants.
Example: High Performance Media (HP-CCM)
High performance media samples were prepared for the growth of mammalian cell cultures and analysed using the S4 TStar.
A 1 ml mixture was prepared in a micro reaction tube of the following components:
- DMEM or HP-CCM: 700 µl
- Ethanol: 290 µl
- Internal standard V (1 g/l): 10 µl
The mixture was homogenised and 10 µl was transferred onto a quartz disc. The samples were then dried on a heating plate at 30°C.
The samples were measured with the Bruker S4 TStar benchtop TXRF spectrometer.
Mo-K excitation was used at 17.5 keV and W-L excitation at 8.4 keV. The measurement time was 1000 seconds. If higher throughput is required, this can be reduced significantly.
2-8 samples of each cell culture type were tested (Human Embryonic Kidney (HEK), Chinese Hamster Ovary (CHO), Baby Hamster Kidney (BHK), Invertebrate (IKZ)). Various micro nutrients and contaminants were detected at concentrations ranging from around 1 – 10 ppb, as shown in the graph below:
The chart below shows the limits of detection for nutrient and trace elements in two different cell culture media (CHO and feed) and the two excitation modes (Mo-K and W-L).
HP-CCM contains a high level of sugars – about 8 g/l in the CHO medium. Despite this, by preparing the samples with ethanol, low detection limits down to 1.5 ppb were achieved for CHO and Mo-K excitation. Even feed media with 20 g/l glucose could be analysed down to 7 ppb.
As you can see in the chart below, the common X-ray tube with Mo target is best for detecting elements in the Mn to Y range. W-L radiation is more suitable for light elements. Using W-L excitation improved the detection limits for the Mg to Cr range by a factor of 2 or more.
More examples are available in an application note from Bruker. The note includes detailed workflow and results for:
- Commercially available DMEM (Dulbecco’s Modified Eagle’s Medium)
- HP-CCM samples spiked with trace metals
Bruker S4 TStar
The S4 TStar is a benchtop TXRF system for research, routine and QC laboratories:
- Plug and play functionality
- Low running costs – a cost-effective alternative to ICP
- 24/7 operation for overnight routine analysis
- 90 sample capacity
Blue Scientific is the official UK and Nordic distributor of Bruker TXRF. We’re here to provide quotes and answer all your questions – just get in touch: