DNA multiplex hybridization on microarrays and thermodynamic stability in solution: a direct comparison

Area of Science:

• Molecular Biology
• Biophysics
• Genomics

Background:

• Microarray hybridization is a key technique for DNA analysis.
• Accurate thermodynamic stability prediction is crucial for DNA applications.
• Existing models may not fully capture the stability of DNA with mismatches.

Purpose of the Study:

• To directly compare DNA hybridization intensities on microarrays with thermodynamic stabilities in solution.
• To evaluate the accuracy of the nearest-neighbor model for predicting the stability of DNA duplexes with tandem mismatches.

Main Methods:

• Designed DNA sequences for perfect match and tandem mismatch duplexes.
• Measured thermodynamic parameters (DeltaH°, DeltaS°, DeltaG°) using differential scanning calorimetry.
• Compared solution thermodynamics with microarray hybridization intensities from 63 experiments.

Main Results:

• A linear relationship was observed between microarray hybridization and solution thermodynamics for most duplexes.
• The nearest-neighbor model generally predicted lower stability for mismatch duplexes than experimentally observed.
• Duplex length and mismatch position influenced deviations from linearity.

Conclusions:

• Tandem mismatch stability is highly dependent on flanking Watson-Crick base pairs.
• Accurate thermodynamic prediction requires considering at least four base pairs (mismatch and flanking pairs).
• Further evaluation of thermodynamic parameters for tandem mismatches is necessary.