What is Cell-Free DNA?

What is Cell-Free DNA?

Recent medical breakthroughs in the early 2000s have discovered cell-free DNA as a new diagnostic marker in the circulating blood in humans. As the name implies, cell-free indicates DNA that are found freely in the blood without a nucleus, as DNA is usually found in a cell enclosed in a nucleus. Though cell-free DNA can also be found in the circulatory system of healthy individuals, their concentrations are at very low to negligible concentrations. However studies have found that the concentrations in cancer patients can reach high levels to substantiate diagnostic significance. With numerous studies conducted, it is now a well recognized fact that tumour DNA is liberated into the circulatory system during necrosis and apoptosis.

Furthermore the diagnostic significance of this cell-free DNA is not limited to just cancer patients; as other medical conditions such as graft rejection, stroke, trauma and burns where cellular damage is present, have similar observations too.

Medical and Diagnostic Significance of Cell-Free DNA

Cell-Free DNA can be excreted into the blood stream by both normal and tumour cells usually through either necrosis and/or apoptosis.

Apoptosis is a highly regulated process to “remove” cells that have reached their senescence stage and are replaced by new functionally healthy cells to prevent “over-population” of cells. In an average adult, between 50 and 70 billion cells reach senescence each day and undergo apoptosis. Apoptosis in normal tissues consequentially cleaves DNA into small 185-200bp fragments.

Tumour cells usually undergo necrosis which is an uncontrolled cell death resulting in loss of cell membrane integrity, resulting in the release of DNA fragments in various sizes and can be longer than 200bp.

Early detection has always been a focal point to improve cancer cure rates. Hence there is an increase in interest in looking for assays that can detect Cell-Free DNAthat correlates with specific cancer cells.

Image 1: In normal circumstances, DNA is usually enclosed in a nucleus in cells. However during apoptosis, both normal and tumour cells will release DNA fragments into the blood stream. The presence of these free circulating DNA can be of diagnostic values if the right assays are created to detect or identify the DNA sequence.

Streck Cell-Free DNA BCT

Previously, there are some major challenges to overcome before any research can be done on the cell-free DNA. This is mainly due to lysis of cells found in the blood, especially from leukocytes as these cells contain their individual genomic DNA. These cells are susceptible to losing their cellular genomic DNA into the plasma during blood processing, storage and shipping leading to contamination of the cell-free DNA of interest in the plasma. Furthermore, traditional cell-stabilising reagents such as formaldehyde and glutaraldehyde have the potential to damage the double helical structure of DNA.

Streck came out with a specialized blood collection tube that eliminates the aforementioned challenges. This Streck Cell-Free DNA BCT is a 10ml draw tube that contains K EDTA as anti-coagulant to allow plasma to be collected upon centrifugation. The signature feature of this product is the stabilising agent; a formaldehyde-free patented preservative that stabilises the blood cells, eliminating the possible contamination of genomic DNA from the leukocytes and most importantly maintain the cell-free DNA structures without interference in the downstream PCR testing.

Image 2: Streck Cell-Free DNA is a specialized vacutainer tube that can be used for direct blood draw. This tube can contains the necessary reagents that can allow immediate extraction of plasma after centrifuging.

Author:

Ivan Medical Technologist I http://textbookhaematology4medical-scientist.blogspot.sg/ Covance Asia Pte Ltd 1 International Business Park, Singapore 609917

Disclaimer: Any views or opinions presented in this post are solely those of the author and do not necessarily represent those of the company or manufacturer. The author accepts no liability for the content of this post, or for the consequences of any actions taken on the basis of the information provided.

Medical Technologist/Scientist vs Nurses

 Medical Technologist/Scientist vs Nurses

WHY are our credentials being undermined? Is it our own fault or is it that we do not get enough media coverage/exposure about our job.

The aim of this post is not about pulling down the importance of nurses to “glamorize” our importance, but its about how we can maybe learn from our counterparts to bring more credit to our jobs.

Here are 3 points that I feel we are lacking in when comparing to the nurses. I have my ultmost respect to the nurses as they play an indispensable and noble role in healthcare.

Point-of-care-Testing (POCT)

For those of you who might know what this means; its medical testing done by nurses near the sites of patient care using either small hand-held devices or small bench analyzers. The goal is to collect the specimen and obtain the results in a very short period of time. There are numerous POCT kits that can do important medical tests such as HcG, INR, CRP, HbA1c, Urine Strips testing to name a few.

So the point I want to make is that, the nursing industry is seeking ways to improve themselves and coming out of their comfort zone to make their jobs more fulfilling and well-rounded. These are very beneficial improvements made to healthcare and will add on more credit to the nursing field.

So the question is, have we as laboratory professionals improved ourselves? Have we contributed to any value-added services to the healthcare? From what I have seen so far, what was I doing 5 years ago and 5 years later, its almost the same. I might be wrong and some of you might disagree with my sweeping statement. Other than technological advances, our job scopes have been very similar. This brings me to the next point...

Contributing innovations and laboratory improvements

In order to gain credit, we need to make good changes and provide more value-added services. Performing clinical tests accurately and meeting turn-around time has become a basic necessity as clinical laboratory professionals. If the nurses can come out of their comfort zones and acquire new knowledge to take up new skills, so can we. We should take initiatives to either think of improvements or ways to improve the healthcare too.

Now here is an example of how one of my seniors makes a beneficial improvement.PBMC isolation is a research test that constantly requires the removal of supernatant throughout the procedure to create cell pellets for storage for future research purposes. Previously, a Pasteur pipette is being used to slowly aspirate the supernatant which can be a very time-consuming and tedious task when you have to handle numerous samples. She took the initiative to look for an auto-aspirator that will perform this task more efficiently and this to me, this is an ingenious idea! This auto-aspirator is a commendable purchase which will help save time (and money because in a business point of view, time = money). She was eventually rewarded handsomely with awards and this brings me to the next point.

Awards and recognition

I think there is a lack of an association to represent the medical technologist/scientist profession. In my knowledge there are only a handful of active professional associations like Australian Institute of Medical Scientists, American Medical Technologist Organisation and Canadian Society for Medical Laboratory Sciencethat I know of.

However in most countries, there is a lack of an association to represent our profession. I feel that this deficiency is causing a lack of coverage and recognition about our profession. In my opinion, having an association can bring about good advantages. It can be an avenue where alike professionals can come together to share experience and inspiration. Some people I know are not very proud about being a medical scientist/technologist and some even left to join a more “socially-acceptable” profession. This could stem from a lack of knowledge of how the career ladder of a medical scientist/technologist looks like. Even I don’t have a clear picture of how it looks like and still exploring. Hence having an association can address some issues like the ones I put forward.

The takeaway message is that I hope to create an awareness regarding issues about our profession so feel free to share your views and thoughts in the comments section. We can all learn more insights together and become better professionals.

Author:                                                                                                                                                  Ivan                                                                                                                                                     Medical Technologist                                                                                                                              http://textbookhaematology4medical-scientist.blogspot.sg/                                                      

Disclaimer: Any views or opinions presented in this post are solely those of the author and do not necessarily represent those of the company or manufacturer. The author accepts no liability for the content of this post, or for the consequences of any actions taken on the basis of the information provided.

Medical Technologist? Whats That?

Medical Technologist? Whats That?

On numerous occasions where I am in a social settings, be it a friends catch up, an old classmates gathering or maybe even a wedding dinner, I will face questions regarding my career. So the most obvious answer will be an honest answer (ofcourse right?); Medical Technologist. This will usually end up with blank stares or raised curious eyebrows. Medical Technologist is a job or career which is so under-mentioned, under-informed, under-publicised, under-recognised and the list goes on. I am not sure whether my fellow colleagues or people I know that are working in the same field, face the same challenge as I do. I struggle to make a positive impression whenever I have to explain about my career.

Due to this reason, I have decided to make a “worded” description about what my career is all about. This is to allow me to have a clearer understanding on how to make an effective description of my job scope without the scientific “expletives”. To some readers (I hope there is...) of this post it maybe an informative post to describe my position.

Basically, I am a Medical Technologist working in the Haematology departmentin a Clinical Research Organisation which deals with clinical trials of new drugs that are yet to be approved for medical usage. I will now give 3 succinct points to summarise what I do and what am I.

Point 1

As the name Haematology implies, which is the study of blood cells, I deal with mainly human blood samples. These blood samples are usually delivered from hospitals where patients are housed in or come for their regular visits for treatment. To put in layman terms, these patients are like “experimental-mice” where pharmaceutical companies need to test the effectiveness and safetyness of their “new drug”.

From the haematological point of view, my job is to ensure that the drug is not adversely affecting the “health-status” of the blood. There are numerous haematological parameters that must be tested and my job is to review this information with scientific knowledge to provide in-depth descriptions. Subsequently, this important haematological information is relayed to the doctors for them to make medical decisions.

Image 1: the blood can be centrifuged (spun at high speed) to separate into different "layers" which can be classified into different cells or components. The quantity, characteristics and size of these cells can tell what a patient is suffering and the health status of an individual.

Point 2

Being in a Clinical Research Organisation, means that there is a fair share of research being done other than the basic clinical testing that can also be found in hospital-based laboratories. I perform sophisticated skills and techniques to isolate specific cell types for research purposes. This is a highly complex department where White Blood Cells are being isolated.

A basic knowledge for all readers; Red Blood Cells do not contain DNA or any genetic materials; hence it has little to no research value. White Blood Cells have a “compartment” called nucleus to contain genetic material that can provide vital information about diseases and therefore have crucial research value.

Point 3

I am not a doctor, neither am I able to give prescription to patients. I am basically a scientist performing sophisticated scientific technical skills to produce medical information to influence the doctors’ clinical decisions.

Imagine a triangular 3 characters relationship; the patient, the doctor and the Medical Technologist – me. An unwell patient is admitted into hospital due to a severe disease, the doctor is there to observe physical symptoms that are visibly displayed externally on the patient. The doctor will then call for some blood tests to be done and here comes my role in performing the necessary testing ordered by the doctor. Once the testing of the blood samples are done, we will send the results back to the doctor for them to either diagnose or make medical decisions.

In conclusion, the role of a medical technologist is as important as a doctor. We as medical technologist are highly educated personnel providing “internal” information. The doctors are ofcourse even more educated to use both visual inspection and these “internal” information to treat the patients and ensure their recovery.

Image 2: The Medical Technologist take center stage here in between the doctors and the patients. This describes the relationship of these 3 roles. The doctor will order and obtain the necessary blood samples and tests from the patients. Subsequently, the medical technologist will analyse these samples and submit the test result reports to the doctor. Finally the doctor will make medical decisions and diagnosis to treat the patient. This cycle will continue on until the patient has fully recovered.

Disclaimer: Any views or opinions presented in this post are solely those of the author and do not necessarily represent those of the company or manufacturer. The author accepts no liability for the content of this post, or for the consequences of any actions taken on the basis of the information provided.