7 DBS Solutions
Dried blood spot analysis is a useful, but not yet perfect, technique. Here are solutions to some currently vexing issues.
Bert Ooms |
- Heat stabilization
Problem: Degradation of analytes during drying due to enzymatic activity.
Solution: Heat the samples for 30 secs.
Caveat: Degradation still occurred with three of six analytes tested.
Reference: 1.usa.gov/YrWqPb
- Heat stabilization
Problem: Degradation of analytes during drying due to enzymatic activity.
Solution: Heat the samples for 30 secs.
Caveat: Degradation still occurred with three of six analytes tested.
Reference: 1.usa.gov/YrWqPb
- On-card derivatization
Problem: Complex handling procedures are needed to derivitize thiols.
Solution: Pre-treat cards with 2-bromo-3'-methoxyacetophenone, dramatically simplifying the workflow.
Reference: 1.usa.gov/17Jyppy
- On-line desorption
Problem: Direct desorption techniques suffer from ion suppression, Interference and low sensitivity.
Solution: Online desorption to an SPE cartridge followed by online elution to LC–MS/MS results in excellent precision and linearity
Next: Online full-spot analysis to circumvent spot-size variability caused by hematocrit variations.
Reference: 1.usa.gov/140R4uY
- Therapeutic protein analysis
Problem: Biopharmaceutical industry wants to reduce pre-clinical animal use.
Solution: Direct enzymatic digestion of DBS followed by LC–MS/MS to identify signature peptides.
Reference: 1.usa.gov/12dvFxi
- Paperspray MS
Problem: Therapeutic drug monitoring with DBS tedious and difficult to automate.
Solution: Spraying directly from triangle-shaped DBS paper into MS/MS provides adequate performance with simplicity.
Reference:1.usa.gov/YrWw9H
- Direct liquid junction DBS
Problem: No single assay for both screening and diagnosis of hemoglobin variants.
Solution: Liquid junction-based extraction and direct infusion into high resolution MS.
Reference: 1.usa.gov/OmADpM
- Colorless samples
Problem: Colorless samples (e.g., liver microsome incubation) are difficult to visually inspect on DBS card.
Solution: Spotting colored dye on card first indicates presence of samples as colorless patch.
Reference: bit.ly/Yrsq69
Bert Ooms is principal scientist at Spark Holland and holds a degree in analytical chemistry. He has been involved in instrumental development of (U)HPLC and automated front-end sample handling for more than 30 years. As former head of R&D, research manager and new business development manager, he has been at the forefront of product innovation at every stage of his career.