Applications/Sample types/Biological Fluids

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Resources for working with biological fluids
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Model Organisms
Biological Fluids

Biological fluids

Biological fluids may be the starting point for a wide range of experimental investigations from discovery protein interaction studies, preclinical toxicology assessments, through to large clinical trial biomarker measurements. For example monitoring biomarkers in saliva is growing in interest because of the ease of collection from patients. Biofluids including plasma, serum, saliva, urine, CSF, synovia and others are compatible for processing with our iST or iST-BCT and iST-NHS kits.

The PreOmics kits are suitable for use in research and regulated environments. The kits contain all you need for your peptide or protein sample preparation and are suitable for use by all members of your lab, no specialist experience is needed. The flexible formats of single samples or racked in to 96 well holders allow the kits to be used manually or with a range of automation options.

The catridges can be processed by centrifugation or using positive pressure manifolds, again giving options for all labs. Dedicated resources are shown below and our technical support team would be happy to help with advice.

Outline processing considerations: Samples with volumes of 1-11 µL can be directly mixed with appropriate LYSE buffer as described in the regular protocols. Volumes higher than 11 µL either require prior precipitation, concentration or mixing with our higher concentrated lysis buffers. Please ensure that the total protein present is within the range 1 – 100 µg.

Non-depeted plasma/serum samples:

Non-depleted human plasma and serum have a high protein concentration, commonly around 50 µg/µL. For processing of non-depleted plasma/serum, mix up to 2 µL plasma/serum with 50 µL LYSE-BCT/ LYSE-NHS buffer and continue with the regular iST-BCT/iST-NHS protocol.

Depleted plasma/serum samples:  

Depending on the depletion process, depleted plasma/serum may contains high salt and/or have a large resulting volume, making the samples incompatible for direct processing with our iST-BCT/iST-NHS kits. It is usually necessary to perform a protein precipitation and use the resulting pellet as input material for our regular iST-BCT/iST-NHS protocol. .

CSF samples:

For highly concentrated CSF samples, follow the recommendations for non-depleted plasma/serum. For diluted CSF samples (volume larger than 25 µL), perform protein precipitation and continue with the regular iST/iST-NHS protocol.

Urine samples:

Protein concentrations in urine samples vary substantially.We recommend to either perform protein precipitation or to perform proteinconcentration using concentrators. As a rule of thumb, 10-100 mL human urinecorresponds to ~100 µg protein, which needs to be concentrated down to 100 µL.Specifically for urine preparations, PreOmics provides an extra WASH0 buffer to effectively remove bilirubin contaminations


Protein concentrations in saliva samples vary substantially, a rough estimate is about 10 µg/µL. Either collect ~10 µL saliva by spitting into a microcentrifuge tube or perform mouth swab and place the swap in 50-100 µL LYSE / LYSE-NHS buffer to fully cover the swap. Keep all other buffer volumes as indicated in the regular protocols.

PreOmics Values


Improved sample quality

High reproducibility: R
Working range: 1-100µg
Increased peptide and protein identifications


Quicker methodology

Less than 2.5 hours for complete workflow
Single step incorporating lysis, reduction and alkylation
All-in-one solution, all reagents provided
Compatible with standard lab equipment


Cleaner peptides ready for analysis

Dual clean up step removes hydrophilic and hydrophobic contaminants
Achieve ready-to-measure peptides
Reduce mass spectrometry downtime
Suitable for a range of processing options


Applying the science
Find out more about the wide range of applications and sample
types to which PreOmics technology has been successfully applied