When working with sample-limited applications such as single-cell proteomics or other precious biological samples, maximizing sensitivity is critical.
Every step of the LC-MS workflow matters when only a small amount of material is available. One important factor is the inner diameter of the nanoLC column. Moving from a conventional 75 µm i.d. column to a narrower 30 µm i.d. format can provide substantial gains in sensitivity for low-input analyses.
Why Column Inner Diameter Matters
In nanoLC-MS, reducing column inner diameter can increase analyte concentration as peptides elute from the column. When combined with appropriately reduced flow rates and efficient electrospray ionization, this can improve MS signal intensity and make low-abundance analytes easier to detect.
This advantage becomes especially important when sample quantity is the limiting factor rather than instrument acquisition time.
More Peptide Identifications in Sample-Limited Workflows
The benefit of narrower nanoLC columns has been demonstrated in published proteomics research.
In a study by Zhu and colleagues, a 30 µm i.d. LC column produced 6,999 unique peptide identifications, compared with 5,309 unique peptides using a 75 µm i.d. column under the conditions evaluated.
That represents approximately a 31% increase in unique peptide identifications.
The study illustrates why narrower-bore separations can be particularly valuable for single-cell and other sample-limited proteomics applications, where recovering additional peptide information from a limited amount of material can have a meaningful impact on overall proteome coverage.
Comparison of 75 µm and 30 µm i.d. LC columns. Published data adapted from Zhu et al., International Journal of Mass Spectrometry, 2018, 427, 4–10.
Higher Signal with MicrOmics 30 µm Columns
MicrOmics has also evaluated 30 µm i.d. integrated nanoLC columns against our 75 µm i.d. columns.
Under the conditions tested, our 30 µm i.d. integrated columns produced approximately 2–3× higher MS signal compared with the 75 µm i.d. format.
The increased signal can provide additional analytical headroom when working with extremely limited sample amounts, helping researchers extract more information from precious samples.
Designed for Low-Input LC-MS
MicrOmics 30 µm i.d. nanoLC columns are designed for researchers who need high sensitivity without giving up the practical advantages of a robust column format.
Available configurations include integrated-emitter, cartridge, classic-column, and bare-column formats, providing flexibility for different LC-MS platforms and laboratory workflows.
The integrated-emitter configuration combines the analytical column and electrospray emitter into a single flow path, reducing unnecessary post-column connections and helping support efficient low-flow electrospray operation.
When Should You Consider a 30 µm i.d. Column?
A 30 µm i.d. nanoLC column can be particularly useful when analytical sensitivity is the primary priority. Applications may include:
- Single-cell proteomics
- Low-input proteomics
- Rare or precious biological samples
- Laser-capture microdissection samples
- Limited clinical or biopsy material
- Applications targeting very low-abundance analytes
As with any nanoLC method, the optimal column configuration depends on sample amount, gradient length, flow rate, LC system, mass spectrometer, and experimental objective.
Sensitivity Where Every Sample Counts
For abundant samples, researchers can often compensate for sensitivity limitations by injecting more material. Sample-limited experiments do not provide that option.
In those applications, improving the efficiency of the separation and ionization process becomes increasingly important.
Narrow-bore 30 µm i.d. nanoLC columns provide one way to increase sensitivity at the chromatography-MS interface and can help researchers obtain more information from extremely limited samples.
MicrOmics offers 30 µm i.d. column configurations for researchers developing high-sensitivity nanoLC-MS and proteomics workflows.
Explore MicrOmics NanoLC Columns
Looking for a column configuration for a sample-limited or high-sensitivity LC-MS workflow? Explore MicrOmics nanoLC column technologies or contact our team to discuss your application.
Explore NanoLC Column Technology →
For technical questions or help selecting a column configuration, contact sales@micromicstech.com.
Reference: Zhu Y. et al. International Journal of Mass Spectrometry. 2018;427:4–10.
Performance results can vary with sample type, LC conditions, mass spectrometer, flow rate, gradient, and other experimental parameters. Comparative results described above reflect the specific conditions used in the referenced study or MicrOmics testing.
