After taking a DNA test for ethnicity, many ancestry companies will give you the option to contact their other customers, providing you share sections of your autosomal DNA with them (meaning that you’re related to these individuals to a greater or lesser degree). The companies that do this maintain ‘Family Finder’ databases, and the people you’re related to are usually referred to as ‘matches’. The three largest companies that do this are Family Tree DNA, and 23andMe, and as part of the results that they provide, you’ll be able to see a list of these living relatives ranked according to how closely you’re related to them.
I was interested in the ethnicity test provided by African Ancestry because of their claim to be able to place your ancestry in a current African country or region. However after reading multiple reviews, I'm hesitant to spend $300 to find out my ancestors are "West African" or from Sub Sahara Africa. Is there any company whose test can place Ancestry within a specific region of African?
Once your genetic information is out there, it’s difficult to undo. Also, once you know something about yourself, it’s impossible to forget. Revelations such as having different parents than you expected or finding unknown half-siblings are difficult to process at any age, but it’s particularly troubling for kids. However, you can always simply opt out of family matching features.
The most important part of this process is registering your kit before shipping it. All five services require this, and if you don't do it, you won't be able to access your results. This requirement is to protect your privacy—your name won't appear on the kit or the results—and to easily track your kit as it goes through the process. Of course, when you sign up for an account with these services, your identity will be associated with it, but the sample and any reports stored on the service's end will just have a unique barcode.
While FTDNA is currently the only company to offer an advanced and full featured chromosome browser (the ability to analyze your results and compare matches by chromosome), MyHeritage now offers a nice integration of a simple chromosome browser right on each match page. 23andMe does not offer a browser but does show your ethnicity “painted” on your chromosomes and Ancestry does not offer this service at all.
When my results appear, they show nothing bad. If anything, it’s anticlimactic: cholesterol, vitamins, liver proteins and the like are all in the normal range, with only ferritin (iron stores) slightly high, with a recommendation to go easy on any iron supplements. My problem with the baseline test is that, unlike Thriva’s other products, clients are supposed to have one every three months to keep track, but would I really want (or indeed need) to do such a test so regularly?
Your DNA information is gathered using saliva capture, which, once analyzed, is stored forever on 23andMe's servers. The service also provides for a chromosome browser and comparison, as long as any possible matches approve your access. The service's matrilineal and patrilineal line testing can geolocate your DNA ancestry in more than 1,000 regions. 

MyHeritage shows cousin matches as part of your DNA purchase for free and has some really wonderful tools to connect your research to your DNA matches. Using smart matching features to see how your tree is connected to others, and adding records you discover this way, may cost an additional monthly fee however. Still, MyHeritage is generally less expensive than Ancestry. You can also try their record collections for free here.
It is very important that you take the time to read the privacy policy, terms and conditions and consent forms associated with any DNA test you take or any site you choose to upload your data to. While FTDNA has a proven track record of protecting the privacy of its users, there have been serious concerns over how AncestryDNA and 23andMe have used data in the past, as well as how they may use or sell your data in the future. Please read this article from Roberta Estes for more information on this issue. MyHeritage states that their consent form (that would allow sharing or selling of your results in aggregated data) is optional.  You can read more about that on The Legal Genealogist, who compliments MyHeritage DNA on their policy and openness.
One of the most popular reasons for doing a DNA test is to determine ethnicity.  Many people start out on their DNA journey trying to learn about their ethnicity and end up discovering new family members, or learning something really cool about their family history.  Is there such a thing as a DNA test for ethnicity, and if so, which one is the best?
In testing, we found that many tests have much more specific and detailed results for European ancestry than anywhere else. This is due more to the diversity of the database than size. For example, AncestryDNA has the largest database with over 10 million samples yet results for Asian ancestry are markedly less specific than results from several companies with much smaller databases, including 23andMe and Living DNA.
There are mixed reactions to the use of ancestry DNA databases in criminal cases. On one hand, the rise of readily-available DNA information for millions of people has led to the arrests of several suspects related to long-cold cases, including the arrest of the Golden State Killer. On the other hand, law enforcement accessing private databases of genetic information from consumers raises several questions regarding privacy and ethical issues.

Most direct-to-consumer DNA test companies warn that the tests may reveal things you wish you didn’t know about your family. For example, you could find out that one of the people who raised you isn’t your biological parent or that there’s an entire branch of your family you didn’t know about. There isn’t a way to prepare for a shock like that, but you can opt out of a company’s family-matching services if you’d rather not know.
I like that with just one exception - the copying of DNA is remarkably accurate (equivalent of copying out encyclopaedia britannica several times with no mistakes) and Protein synthesis is even more accurate. If this weren't true, the organism would swiftly die. Variation, both inter and intra species, is caused by quite different processes - namely crossing over and random assortment of chromsomes during meiosis and then recombination during fertilisation. But I like the storage and pages part of the analogy
More controversially, some of these kits profess to tell you your biological (as opposed to actual age) by measuring the length of your telomeres (in basic terms, the caps at the end of each strand of DNA that protect chromosomes, like plastic tips at the end of shoelaces). Other tests, such as 23andMe, predict higher risks of developing serious conditions, such as multiple sclerosis, Alzheimer’s and Parkinson’s, including the test for BRCA1/BRCA2 (breast and ovarian cancer) that Angelina Jolie famously underwent, going on to have a preventative double mastectomy and surgery to remove her ovaries.
Last month I did the Heritage DNA , because of one of my cousins did the test ,but hers was done by Ancestry ,I was very surprise by the result , we have nothing in commune , i was very concert concern with my result , just because it shows nothing from my family side, supposedly I’m 79.7 % Central American , 13.9% Iberian and 6.4 Scandinavian My whole family is from South America ,so why 79.9 Central American ,any way I was so intrigue that I did the Ancestry Test now , I’m waiting for the result and I’m dying to see the results

— Once you have chosen a test and received your autosomal results there is still a great deal more fun to be had. Independent tools and websites created by scientists and enthusiasts allow you to take the raw data provided from FTDNA, 23andMe and Ancestry DNA and explore them in astounding detail–giving you a wide variety of new admixtures, phasing options, chromosome browsers, SNP tools and connections with family across the world. Gedmatch is our favorite because they have so many wonderful and meticulously updated tools from a variety of sources. Easily upload your raw data and run your results for free (if you love the tools, don’t forget to donate and uncover even more options.)