Molecular Methods, Sequencing Technologies, and Data Interpretation
Choosing the Right Molecular Assay
Platform selection
A strong molecular study matches the assay to the biological question, considering resolution, sensitivity, throughput, bias, and cost. No single technology is optimal for every layer of biology.
Major technologies
| Technology | Best for |
|---|---|
| Sanger sequencing | Targeted validation |
| Short-read NGS | High-throughput variation and expression profiling |
| Long-read sequencing | Isoforms, structural variation, repeat regions |
| Mass spectrometry | Proteomes and post-translational modifications |
| Cryo-EM | Macromolecular structure |
Short-read vs long-read sequencing
Short-read
- High accuracy and throughput
- Excellent for quantification and variant calling in many contexts
Long-read
- Better for full-length isoforms and structural variation
- Useful in repetitive or complex loci
Bias and batch effects
Library prep, amplification, mapping ambiguity, and batch effects can dominate the apparent biological signal if not controlled analytically.
Which technology is most appropriate for resolving full-length transcript isoforms in complex gene families?
Long-read sequencing can span entire isoforms and resolve splice combinations.
Correct answer: Long-read RNA sequencing
Why can batch effects be dangerous in high-throughput biology?
Technical variation must be modeled or randomized away.
Correct answer: They can be mistaken for true biological differences and lead to false conclusions
Interpretation checklist
What is the most important reason to include biological replicates in omics experiments?
Biological replicates allow statistical estimation of true variation among samples.
Correct answer: To estimate biological variability and improve inference
What is one advantage of orthogonal validation after discovery in sequencing data?
Independent validation strengthens causal inference.
Correct answer: It confirms that the finding is not an artifact of a single technology or analysis pipeline