OD2 Media

The Silantes O_pticalD_ensity2 Solution Medium represents the high-performance product amongst the Silantes stable isotope-labeled cell growth media. It can be used for the homologous or heterologous expression of isotopically labeled proteins in bacteria or yeast.

The brand name is indicative of the fact that the media are adjusted to achieve a cell density of OD₆₀₀ > 2 within 24 hours with uninduced bacteria (common strains BL21 or HB101). This quality criterion is validated for each batch.

OD2 media are commonly used if inducing the cells at OD₆₀₀ 0.6-0.9 followed by a ~4h incubation. The achieved cell density yields are comparable to 0,4% glucose-M9 media.

If you are looking for a different performance, the Silantes Concentrate Medium might be the right one for you. Learn more about concentrate media here.

Excellent Performance, especially in D₂O

The Silantes OD2 solution media are developed for a high-performance expression of stable isotope labeled proteins. The media are available in a ready-to-use sterile solution and are adjusted to salt conditions for a cell density of OD₆₀₀ > 2 within 24 hours. They can be used to grow organisms in H₂O or D₂O, the latter with a 4-fold delay.

Figure 1 shows the growth curve of E.coli in ²H-labeled Silantes OD2 Solution Medium for E.coli and in 1 % Silantes SILEX Powder Medium for E.coli in D₂O. Both media have the same excellent performance in D₂O and exceed OD₆₀₀ 2.5 in less than 24 hours.

Available in Multiple Variations, Tailored to Your Needs

Silantes OD2 Solution Media are pre-adapted for E.coli or for yeast. They are available as solution in standard pack sizes (100 mL, 200 mL, 500 mL, 1 L) or in bulk sizes and are available in all ²H, ¹³C and ¹⁵N combinations.

The webshop contains a selection of frequently requested products. Please contact our customer service to see the complete product list or for special requests.

No Addition of D₂O or ¹³C-Glucose Needed

As the raw materials D₂O and ¹³C-Glucose become more and more scarce and thus expensive, it is important to explore alternative options to these chemicals, especially for academic applications. One such alternative is the use of stable isotope-labeled complex media from Silantes. All Silantes cell growth media are prepared from uniformly labeled Cupriavidus necator bacterial cell hydrolysate. This isotopically labeled biomass is a perfect nutrient medium for bacteria and yeasts, eliminating the need for expensive ¹³C glucose or D₂O.

Find out more about the D₂O and ¹³C-glucose price dynamics from the article “Why has the price of stable isotopes skyrocketed?”

Cost-Effective

Figures 2 and 3 show exemplary SDS-PAGE comparing the yield of proteins expressed in M9 medium and Silantes OD2 Solution Medium. The figures show enhanced yields for ubiquitin and RNA polymerase α-subunit using Silantes OD2 Solution Medium.

In order to evaluate the cost-effectiveness of Silantes Rich media for your project, the respective costs of a corresponding minimal medium in relation to the protein yield can be used for comparison. For the Silantes OD2 Medium the following applies:

Price Silantes OD2 medium = Price minimal medium + 25%.
> If you achieve a 25% increase in your protein yield by using the Silantes OD2 medium, you save money by using the OD2 medium.

For a number of proteins, we have validated that protein expression can be increased by over 200% using Silantes Rich Medium compared to Minimal Medium.

To validate Silantes Rich Media for your system, contact us for a free sample.

High Standards in Quality Control

Silantes media are tested for reproducibility of the fermentation results. Moreover, each batch is adjusted to yield the same cell density. The isotopic enrichment of > 98 % is validated by mass spectrometry and the biological competence by growth tests. All test results are documented in a quality certificate, which is provided with every delivery.

Medium composition

The medium is based on a Cupriavidus necator bacterial hydrolysate. Below are the literature values for a number of components.

Component	Composition (g/g DCW) *	Source
Protein	0.680	Srinivasan et al. (2002)
Phospholipid	0.050	Gmeiner et al. (1980)
Cofactors and vitamins	0.030**	Ingraham et al., 1983
Cell wall	0.150
Cell wall (Lipopolysaccharide)	0.034	Neidhardt et al. (1996)
Cell wall (Carbohydrate)	0.055	Determined in own study
Cell wall (Peptidoglycan)	0.060 ***	Determined in own study

* DCW = Dry Cell Weight. The values are calculated for an average macromolecular composition of Cupriavidus necator H16 in MR minimal medium with D-fructose. The biomass composition was experimentally measured during the exponential growth phase of aerobic batch cultivation (specific growth rate: 0.2 h-1 average of three samples). The molecular weight of one water molecule was subtracted from the molecular weight of each molecule to account for esterification or peptide bonding.

** The assumption is based on the fact that small molecules make up less than 3 % of the dry cell weight.

*** In this study, carbohydrates made up about 5.5 % of the cell wall. The rest was assumed to be peptidoglycan.

The amino acid composition determined for OD2 medium:

Amino Acid	AA [µmol / l OD2]	%
As	131.8	21.5
Thr	17.5	2.9
Ser	24.9	4.1
Glu	75.7	12.4
Gly	68.0	11.1
Ala	77.7	12.7
Val	19.2	3.1
Met	9.1	1.5
Ileu	15.5	2.5
Leu	32.9	5.4
Tyr	10.5	1.7
Phe	17.7	2.9
His	58.2	9.5
Lys	21.0	3.4
Arg	14.4	2.4
Pro	17.5	2.9
	611.7	100

Related products

Silantes also offers stable isotope labeled reagents for M9 media such as ¹³C-glucose, D₂O and ¹⁵NH₄Cl.

References

Relevant manuals:

• Expression of Stable Isotope Labeled Protein with Silantes Cell Growth Media for E.coli
• Expression of Stable Isotope Labeled Protein with Silantes Cell Growth Media for yeast

Use cases of the Silantes OD2 Medium in scientific publications:

• Mallagaray, A., Creutznacher, R., Dülfer, J., Mayer, P. H. O., Grimm, L. L., Orduña, J. M., … Peters, T. (2019). A post-translational modification of human Norovirus capsid protein attenuates glycan binding. Nature Communications, 10(1). https://doi.org/10.1038/s41467-019-09251-5
• Niesteruk, A., Jonker, H. R. A., Richter, C., Linhard, V., Sreeramulu, S., & Schwalbe, H. (2018). The domain architecture of PtkA, the first tyrosine kinase from Mycobacterium tuberculosis, differs from the conventional kinase architecture. Journal of Biological Chemistry, 293(30), 11823–11836. https://doi.org/10.1074/jbc.ra117.000120
• Pimienta, G. (2004). Structural characterization of a protein/RNA complex : human TAP/NXF1 protein/retroviral CTE RNA. Heidelberg University Library. https://doi.org/10.11588/HEIDOK.00005077
• Borland, K., Diesend, J., Ito-Kureha, T., Heissmeyer, V., Hammann, C., Buck, A. H., … Kellner, S. (2019). Production and Application of Stable Isotope-Labeled Internal Standards for RNA Modification Analysis. Genes, 10(1), 26. https://doi.org/10.3390/genes10010026

Use cases of the Silantes SILEX Powder Medium in scientific publications:

• 2H 13C 15N SILEX Medium for E.coli as substitute to M9: Movellan, K. T., Najbauer, E. E., Pratihar, S., Salvi, M., Giller, K., Becker, S., & Andreas, L. B. (2019). Alpha protons as NMR probes in deuterated proteins. Journal of Biomolecular NMR, 73(1–2), 81–91. https://doi.org/10.1007/s10858-019-00230-y
• 2H 13C 15N OD2 Medium for E.coli as substitute to M9: Botuyan, M. V. E., Nominé, Y., Yu, X., Juranic, N., Macura, S., Chen, J., & Mer, G. (2004). Structural basis of BACH1 phosphopeptide recognition by BRCA1 tandem BRCT domains. Structure, 12(7), 1137–1146. https://doi.org/10.1016/j.str.2004.06.002
• 2H 13C 15N OD2 Medium for E.coli as substitute to M9: Lingel, A., Simon, B., Izaurralde, E., & Sattler, M. (2005). The structure of the flock house virus B2 protein, a viral suppressor of RNA interference, shows a novel mode of double‐stranded RNA recognition. EMBO Reports, 6(12), 1149–1155. https://doi.org/10.1038/sj.embor.7400583

Relevant blog articles:

• Why has the stable isotope price skyrocketed?
• Stable isotope labeled rich growth media
• Applying Silantes Cell Growth Media to study Human RNA Modification Dynamics