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Why to use 0.1N HCl for measuring Morpholino absorbance at 265nm UV

Jim Summerton has written the following explanation of why we recommend measuring Morpholino concentrations at 265 nm in 0.1N HCl.


Monday, November 13, 2017 - 14:33
ON-based drugs approved by the FDA

Here they are so far, the approved oligonucleotide drugs. Note, however, that Morpholinos are oligos but not nucleotides; Exondys 51 (eteplirsen) is the Morpholino drug.

Table 1. ON-based drugs approved by the FDA.

Tuesday, October 24, 2017 - 11:31
Guidelines for morpholino use in zebrafish

If you work with zebrafish or Morpholinos, please read this.

Stainier DYR, Raz E, Lawson ND, Ekker SC, Burdine RD, Eisen JS, Ingham PW, Schulte-Merker S, Yelon D, Weinstein BM, Mullins MC, Wilson SW, Ramakrishnan L, Amacher SL, Neuhauss SCF, Meng A, Mochizuki N, Panula P, Moens CB. Guidelines for morpholino use in zebrafish. PLoS Genet. 2017 Oct 19;13(10):e1007000. doi: 10.1371/journal.pgen.1007000. eCollection 2017 Oct. No abstract available.

Friday, October 20, 2017 - 08:31
Mechanism of uptake of Morpholino oligos in dystrophic (DMD) muscle

This work elucidates the mechanism of uptake of Morpholino oligos in dystrophic (DMD) muscle, including roles for muscle satellite cells and macrophages.

Myoblasts and macrophages are required for therapeutic morpholino antisense oligonucleotide delivery to dystrophic muscle.

Novak JS, Hogarth MW, Boehler JF, Nearing M, Vila MC, Heredia R, Fiorillo AA, Zhang A, Hathout Y, Hoffman EP, Jaiswal JK, Nagaraju K, Cirak S, Partridge TA.

Nat Commun. 2017 Oct 16;8(1):941. doi: 10.1038/s41467-017-00924-7.

Thursday, October 19, 2017 - 10:36
Time for some music! Evo-devo


Wednesday, September 27, 2017 - 11:47
Confirming Specificity

There are several commonly-used strategies for confirming specificity of a Morpholino oligo. These are the five-mispair experiment, the second non-overlapping 5'-UTR oligo experiment (and the similar two oligos against one mRNA experiments), the mRNA rescue experiment, and my current favorite, the Morpholino-in-a-null-mutant experiment.

Wednesday, September 27, 2017 - 08:46
Review of eteplirsen for DMD

Mutation-Based Therapy for Duchenne Muscular Dystrophy: Antisense Treatment Arrives in the Clinic.
Elizabeth M. McNally, Eugene J. Wyatt.
Circulation. 2017;136:979-981.

Monday, September 11, 2017 - 14:04
BLAST homology and specificity controls

I have had many discussions about specificity with a Morpholino user who does very careful BLAST analysis of each oligo prior to ordering. I had previously suggested that about 14 bases of complementary (without significant flanking complementarity) is probably an acceptable level of stability for off-target interactions found by BLAST. However, in light of a new report I agreed that a 13-base complementarity at a splice junction is enough to raise concern. Here is an excerpt of my response to her.


Wednesday, August 2, 2017 - 08:21
Paper on Morpholino specificity and CRISPR-MO combination

Number of inadvertent RNA targets for morpholino knockdown in Danio rerio is largely underestimated: evidence from the study of Ser/Arg-rich splicing factors.

Joris M, Schloesser M, Baurain D, Hanikenne M, Muller M, Motte P.

Nucleic Acids Res. 2017;[Epub ahead of print] doi:10.1093/nar/gkx638.

Tuesday, August 1, 2017 - 14:35
Formatting sequence information for emails (splice modifying oligo designs)

To email sequence information for design of a splice-modifying Morpholino, write introns in lower case and exons in upper case and write the sense sequence 5'-3'. If you show a start codon, put parentheses around it. Here is an example:


All I need for the design are 10 exonic and 25 intronic bases, like this:

Tuesday, July 25, 2017 - 08:02