Issue #40June 8, 20267 studies

90% of CRISPR guide RNA modified with new chemistry maintains full gene editing power

This week brought major advances in making CRISPR more precise, versatile, and powerful—from fully chemically-modified guide RNAs that work as well as natural ones, to new ways of editing crops and treating viral infections.

🧬 Chemically armored CRISPR guides work just as well as natural ones

Scientists created CRISPR guide RNAs where 90-100% of the building blocks are chemically modified—and they still work perfectly for gene editing
The modified guides use exotic chemistry like 2'-amino-RNA and 4'-thio-RNA that makes them much more stable than normal RNA
These super-stable guides maintained or even enhanced editing efficiency in both lab dishes and living animals

Why it matters: Fully modified guide RNAs could be delivered more easily as medicines since they won't break down as quickly in the body, potentially making CRISPR therapies more practical for treating diseases.

🔗 bioRxiv : the preprint server for biology Preprint 🗓️ Jun 5

Key Findings

🌾 New system knocks out 10 crop genes simultaneously without interference

A twin prime editing system achieved knockout rates of 70.5% in rice, 58.6% in maize, and 75.1% in wheat
The system outperformed regular CRISPR by 4.2-fold for editing all three copies of genes in wheat
Researchers successfully edited four genes at once in rice with 22.8% efficiency

💡 This multiplexed approach could accelerate crop breeding by allowing farmers to improve multiple traits simultaneously.

🏆 Top 0.1% journal 🔗 Nature biotechnology Journal Article 🗓️ Jun 5

🎯 Simple dye modification triples CRISPR success in stem cells

Adding cyanine dyes to DNA templates increased precise gene editing by 2-3 fold in human stem cells
The technique achieved 30% editing efficiency in 3D human embryo models—2.5-3 times better than unmodified templates
The dye helps DNA fold into more compact shapes that work better with cellular repair machinery

💡 This cheap chemical trick could make precise gene editing more reliable for studying human development and disease.

🥈 Top 2% journal 🔗 Nature communications Journal Article 🗓️ Jun 2

🦠 Gene editing wipes out hepatitis B virus DNA in infected liver cells

CRISPR treatment substantially reduced viral DNA copies in human liver cells and mouse models of chronic hepatitis B
The editing created small deletions and larger structural changes that disabled the virus
Treatment blocked viral rebound after stopping standard antiviral drugs

💡 Direct targeting of viral DNA could offer a path to curing chronic hepatitis B rather than just suppressing it.

🥉 Top 5% journal 🔗 Molecular therapy. Nucleic acids Journal Article 🗓️ Jun 1

🔬 Engineered Cas13 variants slash toxicity while maintaining gene control

Scientists created Cas13d variants with 2.2-fold higher cell survival by trimming flexible protein regions
The modified system allows switching between different gene control modes using guide RNA design
Researchers demonstrated programmable control of individual genes within multi-gene clusters

💡 Safer RNA-targeting tools could enable more sophisticated genetic circuits for biotechnology and research.

🏆 Top 0.1% journal 🔗 Nature biotechnology Journal Article 🗓️ Jun 2

📊 High-throughput prime editing screen reveals cancer drug resistance genes

A new screening platform called EvoPRIME identified both known and uncharacterized mutations that make cancer cells resistant to osimertinib
The system achieved comparable efficiency to top prime editing methods without suppressing cellular repair systems
Screens revealed that a specific mutation in protein GAB1 activates survival pathways and confers drug resistance

💡 This platform could help identify new therapeutic targets by revealing how cancers develop resistance to treatments.

🥈 Top 2% journal 🔗 Science advances Journal Article 🗓️ Jun 5

🧪 DNA shape constrains CRISPR's ability to unwind target sequences

Cryo-electron microscopy revealed that when CRISPR binds to circular DNA, it can only unwind less than 3 base pairs instead of the full target
The circular DNA's topology prevents the paired DNA strand from moving away, blocking complete target recognition
This explains why CRISPR works differently on DNA with various shapes and topologies

💡 Understanding how DNA structure affects CRISPR could help design better gene editing tools for different cellular environments.

🔗 bioRxiv : the preprint server for biology Preprint 🗓️ Jun 4

Implications

These advances show CRISPR technology maturing rapidly across multiple fronts—from more stable and deliverable components to safer variants and better screening methods. The combination of improved chemistry, reduced toxicity, and enhanced multiplexing capabilities could accelerate both research applications and therapeutic development.

Studies in this issue

Primary sources used for this newsletter.

Fully Modified SpyCas9 Guide RNAs Allow Strong Genome Editing in Cells and Living Organisms
main storybioRxiv : the preprint server for biology2026-06-05PMID 42244699
How DNA Shape Affects Cas9 Binding to Small Circular DNA
key findingbioRxiv : the preprint server for biology2026-06-04PMID 42239195
Using multiple gene edits to reduce random insertion of hepatitis B virus DNA in long-term infected liver
key findingMolecular therapy. Nucleic acids2026-06-01PMID 42221546
Precise multiple gene editing in monocot plants using paired prime editing tools
key findingNature biotechnology2026-06-05PMID 42249131
Controlling multiple bacterial genes independently using adjustable Cas13d systems
key findingNature biotechnology2026-06-02PMID 42230991
Finding functional gene variants using an efficient PE3-based screening method
key findingScience advances2026-06-05PMID 42247518
Cyanine tags on single-stranded DNA improve precise CRISPR gene editing in stem cell embryos by changing DNA packaging and chemistry
key findingNature communications2026-06-02PMID 42230639