Phlebotomist / Lab Technician

Phlebotomist / Lab Technician

Sr. Lab Guy

20 Years Experience

San Bernardino, CA

Male, 52

For 6 years I was a Laboratory Technician in the Air Force Reserves, working all aspects of the laboratory as well as accomplishing "blood draws" (phlebotomy) in every imaginable setting (inpatient and outpatient).  I have also worked in the private sector for hospitals, doctor offices, and clinical lab sites.  This was my primary field for 20 total years (which began with the Air Force training).  I've been in a new career for ten years, though I recall virtually all of my lab science.

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17 Questions

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Last Answer on November 11, 2017

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Why do nurses have to fill up separate vials when they draw blood? Can't you just run the same tests on one sample?

Asked by Marie518 over 1 year ago

Hi Marie518,  Great question.  There are literally thousands of tests that can be run on blood.  But a much smaller number are very very common.  And each test generally requires a specific tube.  For example, a CBC (Complete Blood Count - used to test for anemia, and other things) needs to be run from a "purple top" tube.  The purple top tubes are standardized across the industry to indicate they contain EDTA, an anticoagulant and a preservative.  CBC's need to be run on blood that hasn't clotted (thus a need for an anticoagulant or "anti-clotting" compound).  Other tests, such as for liver enzymes, require that the blood in the tube actually clots.  These tubes are often called "Tiger Tops" (because of their gray and orange mottled appearance) and allow the tech to centrifuge (spin) the tube at high speed to separate off the liquid portion of the blood (which is a requirement for the test for liver enzymes).  It is a bit more complicated than this, but that's the general idea.  If you were to use only one tube for "all your tests", you would probably get some invalid results (falsely high or low) at best, at worst you could ruin an analyzer.

Why do crime investigation lab tests take so long? Like when they say "DNA results won't be known for weeks", is it an actual lab process that takes that long, or just administrative wait times? And can't cops cut to front of line?

Asked by Bo over 1 year ago



Hi Bo, Thanks for your question.  My experience is in the clinical laboratory, where samples from human patients are analyzed.  But analytical laboratories in general can utilize machinery (analyzers) that probably have many things in common.  And one of those aspects could be incubation.  Some tests require that a sample be incubated or left to sit for a period of time before the testing procedure can proceed.  While I have never worked on DNA analyzers, I'm virtually certain that one or more portions of the procedure requires separation and concentration of cellular matter.  That alone could take some time.  And then there is probably time for the concentrated material to incubate properly for meaningful results.  A good analogy is waiting for a bacterial report.  In most cases, the bacteria needs time to grow before it can be analyzed, anywhere from 48 hours to 2 weeks on average depending on the organism.  If a procedure calls for incubation, it is not a step that can be skipped.  And incubation is usually very specific, which is why you have the (sometimes) painfully long wait times, even in high profile cases.  As for skipping ahead in line, yes, a lab manager usually has the authority to allow for that, but it might only make a small difference in the end. 

What volume of blood would someone have to lose to start feeling woozy?

Asked by Bear over 1 year ago

Hi Bear,  It usually takes a lot of blood loss to "feel woozy".  I once had to draw 22 large tubes on a 14 year old boy, and he did fine.  Blood Banks routinely collect 500 ml of whole blood in about a 20 minute time span and most patients feel ok.  The EXACT amount of blood loss is really a question for a physician, because it would depend on the person (age, weight, history, etc.)  You should know, however, that most people feel "woozy" because of the psychology of the blood draw.  They simply fear it, their blood pressures go down, and they (often, under those circumstances) faint.  Most people do quite well fortunately, and rest assured that even many tubes of blood removed is not physically harmful.

What do you think of Theranos and these other start-up companies who are trying to disrupt the medical testing field?

Asked by LeGrange over 1 year ago

Hi LaGrange,  I'll begin by saying I am far from being a legal expert, but in general any lab procedure, including it's machinery and the science behind the testing itself, must be approved by the FDA unless they have special waivers (most often, I imagine, for research and development - I worked for a doctor who had special waivers to research a new therapy, so I know for a fact that it can be done).  According to one article I read they do have a waiver, but for only one test (I believe it was for Herpes Simplex Virus I) and beyond that no further approvals.  How they can legally test is beyond my scope of knowledge, but apparently they have.  And it seems some testing may have been sent to an Arizona main lab, which in general would not be illegal (labs reference out samples all the time for various reasons).  This does indeed "smell fishy" as a potential startup company's attempt at raising capital.  Fortunately, most if not all doctor offices and hospitals rely on approved procedures.  The risk to the public would be hard to assess not knowing the science and proven accuracy (or inacurracy) of the Edison device.  With all the negative publicity and larger companies distancing themselves from this fiasco, I'd bet any new startup ventures would be giving it second thoughts.

Why do you sometimes just need to give a pinprick of blood from your fingertip, while other times they have to fill up an entire tube from your vein?

Asked by Brett over 1 year ago

Hello Brett,  The amount of blood needed for a test depends on a few things.  And I think it's fair to say that most of the common tests rarely need large amounts of blood.  Current machinery and methods allow for small amounts, often tiny quantities, even in the larger laboratories.  So why the "large tubes" anyway?  Because the techs who actually do the testing might need more blood later, either to verify high or low results by "re-running" those tests or to do additional testing if the doctor asks for more (this is very common, especially with inpatients, but it can also happen with outpatient samples).  In this way, you usually won't have to be redrawn.  And statistically speaking, a larger sample would have a better result (though the "smaller sample technology" has been thoroughly vetted so one can rest easy with those results).  The smaller samples, such as for home testing for blood sugars, or sometimes in a doctor's office or at a health clinic, are designed as "screenings", for the most part, and the results are "good enough to give you a good idea" of what your level is (whether that be your hemoglobin, your blood sugar, etc.)  If I prick my finger and use a tiny drop of blood to check my sugar level on a home device, that result will vary if I do it again on a different finger (20 points difference some times - I've tried it!) but I get the gist of "about" where my blood glucose is, good enough to decide medication and meals.  Now on a "big" machine, in a hospital lab?  A larger tube of blood, even if rerun, will show way more consistent results (often the same result!) so a glucose level of 120 mg/dl will be 120 mg/dl plus or minus a small deviation every time it's run on that same tube.  While it's always good to have that level of accuracy and precision, the smaller samples will usually be good enough to get you by and the doctors know this.

How rigorous is the testing that donated blood goes through before it's used? For example, even if a test for HIV is 99.99% effective, can you really risk 1 / 10,000 recipients contracting it this way??

Asked by EnfantTerrible over 1 year ago

Hi EnfantTerrible,  You ask a question that I'm sure is on the minds of many people.  I worked for a short period of time as a phlebotomist/technician in an Air Force blood bank, but as that was some time ago I did a little reading to catch up.  Here's the scoop - the answer to the substance of your question, which is really "Can you get HIV from donated blood?" is in the affirmative:  Yes, it is possible to be infected by HIV through donated blood.  However, as you pointed out, the chances of that happening are incredibly small.  So small that the National Institute of Health website quotes the following, "Only about 1 in 2 million donations might carry HIV and transmit HIV if given to a patient."  So is the risk of "contracting it this way" worth it?  Absolutely.  Think of it this way:  If you knew that you had a 100% chance of losing your life by declining a blood transfusion and a 1 in 2 million chance of contracting AIDS, which would you choose?  Doctors assess risk vs treatment with worse odds than this all the time.  As for how "rigorous" the testing is for donated blood products, they are tested for HIV, Hepatitis B and C, syphilis, and other things as well.  In some cases they even use more than one process, and more than one "marker" (for example, ANTIGENS - specific viral proteins found on the surface of the red blood cell - versus ANTIBODIES - specific proteins the body produces in response to a specific virus).  They make as scientifically sure as they can that the risks are as low as possible.  So low that your choice to receive donated blood to save your life should be a "no-brainer". 



Does the technology already exist for people to do reliable at-home testing and is that being held back for some reason by the medical industry, maybe because it's still a huge profit-generator for them?

Asked by Homer1 over 1 year ago

Hi Homer1,  An excellent question.  Let's take a closer look at what you're asking.  Before we can talk about the available TECHNOLOGY, perhaps we should ask about the specific TESTS.  Every test, from a simple blood glucose to a blood count has it's own set of protocols and science.  Some tests are based on color changes, electrical changes, chemical changes, etc.  In theory, an in-home "analyzer" could be created with today's science.  In smaller ways it already exists.  Diabetics check their blood sugars on a hand-held analyzer called a glucometer.  There are in-home tests for ketones on urine, for pregnancy, even for common drugs of abuse.  Now, I think you may be wondering why the average household can't have it's own analyzer that does all of the most common blood tests.  And the answer is this:  Valid Results.  Even the largest, high volume analyzers must be checked periodically for statistical drift and other anomalies inherent to the system.  In some cases, there has to be calibration (making sure the machine "knows" what a particular value is).  Controls have to be run periodically (another feature that tests the machines reliability).  How would you be certain that your results are valid?  And there is more, much more, not even including the cost of reagents.  But let's say you do have this Household Blood Analyzer.  And let's say you do learn how to use controls for the, oh let's say, 50 odd tests on-board and have been trained in calibrations and error detection.  Great.  You draw a blood sample from yourself, put it in the analyzer, and 10 minutes later or so you have results.  What then?  The analyzer will tell you if something is "too high" or "too low".  But only a doctor can interpret those results.  And for liability reasons alone (not to mention ethical considerations), your doctor's not just going to take the read out from your machine at face value.  He or she would order those tests again, on a certified lab analyzer run by trained professionals.  Yes, the lab industry can be lucrative but it's also very competitive.  Reps are constantly talking to doctor office managers and even the physicians themselves trying to get contracts for their labs.  But none of that has anything to do with an "in-home" system.  In the end, it is the validity of your results that can mean life or death.