Israeli scientist rolls out 15-minute Covid-19 tests

The nationwide vaccination campaign has taken Israel by storm. However, even if the entire population is quickly vaccinated against the coronavirus (Covid-19), additional tests will still be needed for many months. Health officials will still need to quickly map out where infected individuals or populations are located, verify that people are indeed healthy, follow new chains of infection, or test those who’d like to fly overseas. Waiting 48 or even 72 hours for test results harms the test’s effectiveness, and can occasionally deem the results irrelevant. Traditional tests look for the continuous presence of viral RNA coronavirus material in a sample taken from cells obtained from the nasal passages or throat and can take between one and three hours to analyze the concentration of viruses from a sample. Further delays are caused by bottlenecks in the testing labs. Since the outbreak of the pandemic, repeated attempts have been made to speed up the process, and now it seems as though one Israeli scientist has achieved a potential gamechanger.

Various types of rapid tests have already been presented over the past year. The diagnostic test offered by U.S. diagnostic manufacturing company Quidel, was perhaps the most notable, and its Sofia test was later adopted by the Israeli Ministry of Health. Tests such as those don’t look for the actual presence of RNA or other genetic viral material in the infected individual, rather they deduce whether a person is a viral carrier based on other metrics, such as locating the existence of viral proteins related to the coronavirus.

 

Calibrating old technology for rapid testing

The new method is based on rapidly testing coronavirus samples by using the PCR method, which makes millions of copies of DNA samples, allowing scientists to zoom in on a small portion of DNA and analyze it in detail, enabling them to fine-tune their results. Those responsible for the breakthrough include Dr. Amos Danielli and his laboratory technicians at the Faculty of Engineering at Bar-Ilan University. For the past eight months, his team has been working on calibrating MagBiosense technology and adjusting it so that it may be used for rapid Covid-19 testing.

Today, coronavirus samples are taken from supposed infected individuals and the material undergoes a series of chemical manipulations, whose job is to prepare them for an analysis conducted by PCR machines, or quantitative PCR instruments, using a light sensor. After the genetic material, or RNA, is extracted from the sample, it is mixed with a special chemical solution that knows how to spot viral RNA and separate it from the rest of the sample.

The RNA is reverse-transcribed into complementary DNA using the reverse transcriptase enzyme, and multiple DNA strands are encouraged by a specific chemical to multiply rapidly, making a great mass of genetic information, helping scientists zoom in on the minute information, where a specially-equipped light sensor can easily spot individual viral proteins. In addition, the chemical solution is filled with fluorescent molecules that are able to attach to the viral genetic information and “color” it with phosphorescent material that emits light or phosphorescence when a laser is shined upon it. The sensor in the PCR machine knows how to sense light and thereby identify the virus in a sample.

Danielli and his team added additional materials to this ‘chemical salad’ which gives the molecules in the solution a magnetic charge as well. An electromagnet is affixed to the PCR machine so that in real-time the genetic information will be collected and drawn closer to the sensors. In that way, Danielli explains, the identification of Covid-19 in a sample can be much quicker and test a greater amount of genetic information - which is created by the machine - much earlier in the testing process. This in turn allows researchers to determine with high proficiency whether the individual is infected or not.

“It’s like attracting fireflies”

“Think of it like fireflies,” Danielli told Calcalist. “If you see two or three fireflies flying around the room, you won’t be able to spot them. But if you have several concentrated in one spot, you’ll be able to locate them easily. We look at how much light is emitted in the solution, and the amount of light increases at every PCR step, or as the machine’s sensor doubles the amount of genetic information. But if the amount of genetic material that the solution was started with was too sparse, it will take more time to create a large amount of information that the light sensors can detect. We are just helping the sensor do its job and attracting the ‘fireflies’ to it.” He thinks the technology that his lab is developing can successfully shorten the diagnostic testing time, cutting it down from an hour or an hour and a half to just 15 minutes.

The MagBiosense device, (which is the bread and butter of the magnetic biological sensing field), was developed by Danielli’s lab 15 years ago during the course of his doctorate studies, to be used by the agricultural industry and a company he registered in the U.S. (and later sold the technology) to detect diseases in farm livestock. Its first use for human research, however, was conducted four years ago as part of the ongoing struggle against the Zika virus which broke out in Brazil in 2016. With the outbreak of the coronavirus pandemic, Danielli began to adapt the device so that it could be used to identify coronavirus material as part of a collaboration with the Department of Laboratories at the Ministry of Health. During the study, which was conducted at Bar-Ilan University, 274 samples were taken, 140 of which yielded negative-Covid results, while 134 cases were found to be infected with the virus. In 100% of the cases, the results of the MagBiosense test were identical to that of the standard PCR tests, with a typical test taking around 30 minutes.

Now, technological application has reached a point where it can be recruited for easing the bottleneck conditions in diagnostic testing laboratories. Danielli’s testing device was approved by the Administration for the Development of Weapons and Technological Infrastructure, which recommended that the Ministry of Health purchase the technology for widespread use in public laboratories. Danielli believes that the technology has an even greater potential due to its rapid test result time, and can be utilized in places like airports, border crossings, or potential Covid-hotspots with an abundance of travelers, like Eilat or the Dead Sea.

This all joins the long line of Israeli developments in the Covid sector in recent months, which are all looking to optimize diagnostic testing. Prof. Gabby Sarusi at Ben-Gurion University of the Negev is working on developing a rapid exhalation test that analyzes a person’s breath, similar to the breath-analyzer used by the Israel Police to detect drunk drivers’ breath by analyzing the electrical charge emitted from their air flow. The startup LessTests joined the Technion Institute of Technology, and developed a more efficient management of diagnostic testing by mixing several coronavirus tests together and using algorithms to analyze the results and conduct mass testing. During the first few months of the pandemic, the Tel Aviv-based company, ImpactLabs engineered a robot that can quickly analyze Covid-19 samples without human contact. Those two examples could help shorten the long wait time and relieve bottleneck conditions in the testing process.