I’ve heard of PCR before (polymerase chain reaction) where more copies of a DNA sample can be rapidly made. If the problem was that the quantity of blood that Theranos uses is too small, why wasn’t PCR used/ (if it was) why didn’t it work?
Also if I’m completely misunderstanding PCR, if someone could for that too, I’d appreciate it, thank you!
In: 148
Abbott Diagnostics makes a device called an [iStat ](https://www.globalpointofcare.abbott/en/product-details/apoc/i-stat-system-us.html?gclid=CjwKCAjwzeqVBhAoEiwAOrEmzdgAlrkpwgFsIetgEIUdu4NDZYxk1kBCkA6D4C2LXCG2KRndojK2xxoC6FIQAvD_BwE), which actually does a lot of what Theranos aimed for: microfluidic system, small sample volumes, point of care tests, etc. iStat has been on the market for decades, and fills a very good niche role. It’s a lot more expensive and time consuming to do tests in bulk on an iStat, but it’s great when you need one result right now.
Two big limitations on this tech: when you draw someone’s blood, you break a lot of cells, and the stuff inside the cells can throw off some of your tests because it’s different than the stuff inside your blood. If you use a larger tube of blood, that stuff is diluted out enough that it doesn’t affect the results.
The other one is sensitivity. The most sensitive PCR test in my lab needs at least ten viruses per ml in the specimen to accurately detect it. So if I take that kind of sample and split it into 0.1 ml tubes, each tube would only have an average of 1 virus per tube. If I split it into 0.05 ml tubes, half of the tubes statistically wouldn’t have any virus at all, so if I run that on an instrument, it will return a negative result.
pool owner here; new this was bs from the beginning. I have dozens of test all which have to be done separately.
The problem is the amount of steps involved for PCR are numerous – it is pretty complicated. No one that I know of has found a way to simplify the process.
I’m quite shocked that Mattis wasn’t pressed harder on his involvement in Theranos, at his Senate confirmation hearing. I had the opportunity to speak with someone who was on the committee that received Theranos’ presentation to the various reps from the uniformed services’ medical corps. He said they all knew it was bullshit, but there was incredible pressure from the Dept of Defense to push it through.
Pcr needs a primer to bind so you must know what your working with to use it and make sure it doesn’t bind to the wrong the spot
It was promising to detect multiple kind of diseases and predict them before ocurring to any patient by the use of a nano-technology.
When Elizabeth Holmes was taken into a conference with experts and scientist in the matter, they all figure out that it was a complete false invention as she kept invading the important questions specially about numbers. There was a part when she was asked about how many numbers specifically and she couldn’t tell and kept going circles in her argument.
Most expert in the matter kept emphasising that a tiny little drop of blood wont be enough to fun studies in short amount of time that it will not yield to any positive results.
Additionally when her invention was compared to others, it was proven defective and with inaccuracies and she was actually using the technologies that were being in use by competitors.
u/almostrainman has addressed the PCR difference already. (Only works because DNA)
Proper ELI5: Blood tests destroy the blood that they test. We cannot run a bajillion tests on a single drop of blood. Maybe in a hundred years we’ll be able to!
Less proper ELI5: (Kind of assuming high school knowledge here) Theranos was trying to run a ridiculous amount of tests on a ridiculously small sample of blood. It could never have worked without borderline magical R&D work.
If you look at the basic chemistry sets that you use at school: add liquid A to your sample and see if it turns blue. Great, turning blue means that the sample is positive for Copper. Nice work! Now, you want to check the sample for whether it’s got Arsenic in it, but liquid B would turn your sample red in the presence of arsenic. You add liquid B and the sample turns a weird green because it started blue. Now, is liquid B coming up positive for arsenic? Maybe. Liquid B might have reacted with arsenic to produce a positive result, but because it was already blue, it turned an unexpected colour. Or liquid B reacted with liquid A to produce the unexpected colour. Even if it had turned the expected colour of purple (blue+red) you wouldn’t be able to say definitively if that was because of an additional positive result or a weird reaction. You would have to run a crazy amount of tests on control samples just to determine was a positive arsenic test looks like after a positive copper test. Then… you would need to repeat all of that process for the different combinations of positive copper/negative arsenic, negative copper/positive arsenic and negative copper/negative arsenic.
The simplest solution would be to run the tests separately on two different samples of blood, but we’ve only got a single drop to work with. So we would have to check if the test works on half a drop of blood and if it produces the same colour changes/correct results.
Take that example of 2 tests being run on a drop of blood and upscale it to running 70 tests (I think that was their number) on a single drop.
Theoretically, if you came up with a device that could measure something like the electric field of the atoms in the blood (maybe something like that? I’m not up to speed on “micro fluidics”) then you could potentially extrapolate that data to a usable result, but again you would end up having so much data to sift through that I’m not sure you would ever be able to account for all the individual variances that you would encounter. Like “does having a total cholesterol of 5.51397 cause your readable magnesium to increase by 5 points?” or “what effect does taking aspirin regularly, but missing approximated every 12th dose because people are human, have on the measurable electric field of haemoglobin?”
I’m saying all this with the benefit of hindsight, but there was a reason that Theranos dodged inspections and blanket NDA’d everyone that was in the same zip code as one of their machines. Their tech was a fantastic idea but should have been researched harder than it was marketed.
Theranos was promising way more than they could possibly deliver. Multiple blood tests from a finger prick sampling, taken from a device smaller than a laundry basket that was located in walk-in pharmacies and supermarkets that would provide near instantaneous feedback at virtually no cost to the customer. If they could deliver on even one of those promises it would be miraculous but to throw all of that out there? Let us know how you’re enjoying the accommodations in the hoosegow.
The amount of blood obtained from the pin prick was too small to run all the hundred or so tests they claimed, once you divide it for all the tests there just isn’t enough blood left.
The drop of blood was from a capillary in your finger which may have vastly different makeup compared to blood from a vein. Sometimes this is ok eg blood sugar but not all the hundred tests they were claiming to run would have found this acceptable.
Different tests require different blood prep. You might have seen a nurse at the hospital take multiple vials of blood at the same time. This is not because they need all that blood but because certain tests your doctor ordered requires different things to be added to the blood.
The machine was way too small to be doing everything they said it was.
There are companies that are trying to do something similar in concept to Theranos, but scale down capabilities and the be more reasonable in terms of size. But its much more difficult to get funding in this arena now as Theranos poisoned the well.
PCR amplifies DNA. Most blood tests don’t work by looking at DNA but instead specific proteins or salts.
I’ve heard of PCR before (polymerase chain reaction) where more copies of a DNA sample can be rapidly made. If the problem was that the quantity of blood that Theranos uses is too small, why wasn’t PCR used/ (if it was) why didn’t it work?
Also if I’m completely misunderstanding PCR, if someone could for that too, I’d appreciate it, thank you!
In: 148
Abbott Diagnostics makes a device called an [iStat ](https://www.globalpointofcare.abbott/en/product-details/apoc/i-stat-system-us.html?gclid=CjwKCAjwzeqVBhAoEiwAOrEmzdgAlrkpwgFsIetgEIUdu4NDZYxk1kBCkA6D4C2LXCG2KRndojK2xxoC6FIQAvD_BwE), which actually does a lot of what Theranos aimed for: microfluidic system, small sample volumes, point of care tests, etc. iStat has been on the market for decades, and fills a very good niche role. It’s a lot more expensive and time consuming to do tests in bulk on an iStat, but it’s great when you need one result right now.
Two big limitations on this tech: when you draw someone’s blood, you break a lot of cells, and the stuff inside the cells can throw off some of your tests because it’s different than the stuff inside your blood. If you use a larger tube of blood, that stuff is diluted out enough that it doesn’t affect the results.
The other one is sensitivity. The most sensitive PCR test in my lab needs at least ten viruses per ml in the specimen to accurately detect it. So if I take that kind of sample and split it into 0.1 ml tubes, each tube would only have an average of 1 virus per tube. If I split it into 0.05 ml tubes, half of the tubes statistically wouldn’t have any virus at all, so if I run that on an instrument, it will return a negative result.
pool owner here; new this was bs from the beginning. I have dozens of test all which have to be done separately.
The problem is the amount of steps involved for PCR are numerous – it is pretty complicated. No one that I know of has found a way to simplify the process.
I’m quite shocked that Mattis wasn’t pressed harder on his involvement in Theranos, at his Senate confirmation hearing. I had the opportunity to speak with someone who was on the committee that received Theranos’ presentation to the various reps from the uniformed services’ medical corps. He said they all knew it was bullshit, but there was incredible pressure from the Dept of Defense to push it through.
Pcr needs a primer to bind so you must know what your working with to use it and make sure it doesn’t bind to the wrong the spot
It was promising to detect multiple kind of diseases and predict them before ocurring to any patient by the use of a nano-technology.
When Elizabeth Holmes was taken into a conference with experts and scientist in the matter, they all figure out that it was a complete false invention as she kept invading the important questions specially about numbers. There was a part when she was asked about how many numbers specifically and she couldn’t tell and kept going circles in her argument.
Most expert in the matter kept emphasising that a tiny little drop of blood wont be enough to fun studies in short amount of time that it will not yield to any positive results.
Additionally when her invention was compared to others, it was proven defective and with inaccuracies and she was actually using the technologies that were being in use by competitors.
u/almostrainman has addressed the PCR difference already. (Only works because DNA)
Proper ELI5: Blood tests destroy the blood that they test. We cannot run a bajillion tests on a single drop of blood. Maybe in a hundred years we’ll be able to!
Less proper ELI5: (Kind of assuming high school knowledge here) Theranos was trying to run a ridiculous amount of tests on a ridiculously small sample of blood. It could never have worked without borderline magical R&D work.
If you look at the basic chemistry sets that you use at school: add liquid A to your sample and see if it turns blue. Great, turning blue means that the sample is positive for Copper. Nice work! Now, you want to check the sample for whether it’s got Arsenic in it, but liquid B would turn your sample red in the presence of arsenic. You add liquid B and the sample turns a weird green because it started blue. Now, is liquid B coming up positive for arsenic? Maybe. Liquid B might have reacted with arsenic to produce a positive result, but because it was already blue, it turned an unexpected colour. Or liquid B reacted with liquid A to produce the unexpected colour. Even if it had turned the expected colour of purple (blue+red) you wouldn’t be able to say definitively if that was because of an additional positive result or a weird reaction. You would have to run a crazy amount of tests on control samples just to determine was a positive arsenic test looks like after a positive copper test. Then… you would need to repeat all of that process for the different combinations of positive copper/negative arsenic, negative copper/positive arsenic and negative copper/negative arsenic.
The simplest solution would be to run the tests separately on two different samples of blood, but we’ve only got a single drop to work with. So we would have to check if the test works on half a drop of blood and if it produces the same colour changes/correct results.
Take that example of 2 tests being run on a drop of blood and upscale it to running 70 tests (I think that was their number) on a single drop.
Theoretically, if you came up with a device that could measure something like the electric field of the atoms in the blood (maybe something like that? I’m not up to speed on “micro fluidics”) then you could potentially extrapolate that data to a usable result, but again you would end up having so much data to sift through that I’m not sure you would ever be able to account for all the individual variances that you would encounter. Like “does having a total cholesterol of 5.51397 cause your readable magnesium to increase by 5 points?” or “what effect does taking aspirin regularly, but missing approximated every 12th dose because people are human, have on the measurable electric field of haemoglobin?”
I’m saying all this with the benefit of hindsight, but there was a reason that Theranos dodged inspections and blanket NDA’d everyone that was in the same zip code as one of their machines. Their tech was a fantastic idea but should have been researched harder than it was marketed.
Theranos was promising way more than they could possibly deliver. Multiple blood tests from a finger prick sampling, taken from a device smaller than a laundry basket that was located in walk-in pharmacies and supermarkets that would provide near instantaneous feedback at virtually no cost to the customer. If they could deliver on even one of those promises it would be miraculous but to throw all of that out there? Let us know how you’re enjoying the accommodations in the hoosegow.
The amount of blood obtained from the pin prick was too small to run all the hundred or so tests they claimed, once you divide it for all the tests there just isn’t enough blood left.
The drop of blood was from a capillary in your finger which may have vastly different makeup compared to blood from a vein. Sometimes this is ok eg blood sugar but not all the hundred tests they were claiming to run would have found this acceptable.
Different tests require different blood prep. You might have seen a nurse at the hospital take multiple vials of blood at the same time. This is not because they need all that blood but because certain tests your doctor ordered requires different things to be added to the blood.
The machine was way too small to be doing everything they said it was.
There are companies that are trying to do something similar in concept to Theranos, but scale down capabilities and the be more reasonable in terms of size. But its much more difficult to get funding in this arena now as Theranos poisoned the well.
PCR amplifies DNA. Most blood tests don’t work by looking at DNA but instead specific proteins or salts.
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