A plastic rabbit actually has DNA, and every part of its body can be "cloned" | Latest research from Einstein's alma mater

Latest update time：2019-12-11

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A magical thing happened - a plastic rabbit can also have its own DNA .

△ Image source: WIRED

Moreover, by cutting off any part of the rabbit's body, the original rabbit can be "cloned".

This amazing research from the Swiss Federal Institute of Technology in Zurich and Israel's Erlich Lab is the first to inject DNA as an information storage tool into everyday objects.

(ETH Zurich is known as the "first university in Europe". Einstein studied here from 1896 to 1900)

In other words, even the pots and pans in your home can carry "genetic information"!

When an archaeologist thousands of years later obtained a pile of broken porcelain pieces injected with DNA, through gene sequencing, he could not only create an identical bowl, but even restore the appearance of the entire civilization from it.

Sriram Kosuri, a biochemist at UCLA, commented:

The coolest thing about this work is that it proves that DNA can really achieve ubiquitous storage .

This latest research result was published in Nature Biotechnology, a subsidiary of Nature.

How did the 3D rabbit that can store DNA come about?

We know that every living thing has DNA, and today this technology allows inanimate objects to have DNA as well.

The 3D rabbit was printed in a laboratory at ETH Zurich.

Embedded in the rabbit's polymer matrix are tens of thousands of tiny glass beads , each containing dozens of synthetic DNA molecules.

So the bunny itself is a digital blueprint: 370 million data files describing its outline .

This research uses a framework called DoT (DNA of Things).

In this architecture, DNA molecules are fused to a functional material to create objects with immutable memory.

The researchers chose an object called the Stanford Bunny, a commonly used 3D test model for computer graphics.

First, the binary stereolithography (STL) file of the bunny was compressed from 100kB to 45kB.

Next, the file was encoded using DNA Fountain technology into 12,000 DNA oligonucleotides (oligos), the maximum number of oligonucleotides that can be generated by a single CustomArray chip.

The redundancy of DNA fountain encoding is 5.2x compared to the file size, which means that the file can still be correctly decoded even if 80% of the DNA oligonucleotides are missing.

Then, the PCR-amplified oligonucleotides were loaded into SPED (silica particle-encapsulated DNA) beads, which were embedded in polycaprolactone (PCL).

PCL is a biodegradable thermoplastic polyester with a low melting point and high solubility in a variety of organic solvents, making it an ideal material for compounding and printing under mild conditions.

To prepare 3D printing filament, the researchers mixed SPED capsules with dissolved PCL and then extruded the mixture into 2.85mm filament compatible with desktop 3D printers.

Notably, the inclusion of 100 mg kg ⁻¹ (100 ppm) of SPED beads in the filaments did not cause any detectable changes in the mechanical properties, weight, or color of the filaments.

The DNA content of SPED beads is 2 mg per gram , which means that the DNA concentration of PCL filaments is 0.2 mg kg ^-1 (0.2 ppm), which is much lower than the DNA concentration of biological organisms.

Finally, the researchers 3D printed the Stanford Bunny using the same file stored in the DNA-containing PCL filament.

The experimental results show that by using a portable sequencer, data can be perfectly and quickly retrieved from 3D objects with only a small consumption of material.

The researchers cut about 10 mg of printed PCL from the rabbit's ear, which accounted for 0.3% of the rabbit's total weight (3.2 g).

Then, five generations of replication experiments were conducted using the DoT architecture .

There was a nine-month gap between the fourth and fifth generations, which suggests that rabbits have the ability to store DNA for long periods of time .

Moreover, this file can be detected from all five generations of products.

But at almost every round of replication, the integrity of the data deteriorated, and an increasing proportion of molecules were seen to fall off .

Before inserting the DNA into the PCL filaments, the proportion of the original library was 5.9%, while in the last few generations, this proportion exceeded 20%.

To better understand the impact of replication on library composition, the researchers used a binomial distribution to model the number of correct sequence reads for each oligonucleotide.

The researchers said:

Almost any kind of digital information can be stored in DNA.

To demonstrate this, they stored a 1.4M video on DNA and placed it in the lenses of plexiglass glasses.

Using a process similar to the rabbit experiment described above, the team also successfully obtained video files from it.

1kg of DNA can store the world's data

Using DNA to store information is already a relatively mature technology.

DNA has four base pairs: AT, TA, CG, and GC, which are used to encode genetic information.

Binary uses 0 and 1 to encode information, so DNA can use four bases: A, T, G, and C to convert digital signals.

Using CRISPR gene editing technology, any DNA sequence can be created and the corresponding data can be stored.

Also, since there are four types of bases, a character that would normally take 8 bits to represent only requires 2 base pairs when represented by a DNA sequence.

The advantage of DNA storage is that its storage density is far higher than that of electronic devices such as hard disks and magnetic tapes. One gram of DNA is enough to store a huge amount of information. According to previous research by Harvard University, a shoebox full of DNA (about 1kg) can store the world's data .

And so far, only molecular storage technologies such as DNA storage are not limited by geometric shapes on a macro scale.

This opens the door to a new world. Erlich, the author of the paper, said that the technology of injecting DNA that stores information into objects can also be used to create robots that can replicate themselves in the future.

Physician scientist Eric Topol believes that DoT takes the concept of DNA data storage to unprecedented heights, including medical applications.

Another benefit is that DNA is very stable and can survive for hundreds or thousands of years.

When DNA is injected into a variety of objects, it means that future archaeologists may be able to restore the original appearance of a civilization through a pile of broken porcelain pieces.

However, in order to read this information, DNA sequencing is required.

For example, researchers at Harvard University inserted an animated image of a horse riding into the DNA of E. coli.

The bacteria's genome was then sequenced to reconstruct the image with 90 percent accuracy.

Another major challenge of DNA data storage is its high cost. Both DNA synthesis and DNA writing are currently very expensive.

According to Wikipedia, each megabyte costs $12,400 to encode and $220 to retrieve.

However, it was noted that the exponential decline in the cost of DNA synthesis and sequencing, if this trend continues into the future, should make the technology cost-effective for long-term data storage by 2023.

In this regard, Erlich believes that if mass production can be achieved, the price will be greatly reduced.

DNA storage, more than just theory

DNA data storage isn't just theoretical, either.

Last year, Adrien Locatelli, a high school student from France, encoded parts of the Bible and the Koran into DNA chains and then injected them into his body using the AAV2 virus as a vector.

In June this year, Catalog, a Harvard-based startup, encoded 16GB of English Wikipedia content on a DNA chain.

In July, Catalog announced that it had successfully stored 1TB of data on DNA weighing only grams, and said that it would begin commercialization next year.

Now, this 3D printed rabbit with genetic material has taken another big step towards "DNA-of-things".