Three of the companies, MyHeritage, Ancestry and FTDNA, use the Illumina OmniExpress chip and 23andMe uses the new Infinium® Global Screening Array chip from Illumina. The fact that all of the chips come from the same company may be confusing, leading some to believe that all tests are created equal. This is not the case. The chip used to process DNA samples is only one part of the process. Each company develops their own analysis of the results, references different population samples and provides different reports. In addition, each one of these DNA test providers offers different tools for you to analyze the data you receive, creating variations in results, accessibility and usefulness.
Some ethnicity DNA tests will report on the percentage of your autosomal DNA that can be linked to Neanderthals and/or Denisovans – these are non-human ‘hominin’ species that inter-mixed with humans before dying out tens of thousands of years ago. The percentage of our DNA that originates from hominins is 1-5% and it varies greatly between individuals. Only a few genetic ancestry companies include this analysis in their tests (e.g. 23andMe and National Geographic’s ‘Geno 2.0’) and it can be fun to see how much of these ancient species still live on in your genetic code.
Genes make up the blueprint for our bodies, governing factors such as growth, development and functioning. Almost every cell in the human body contains a copy of the blueprint, stored inside a special sac called the nucleus. The estimated 23,000 genes are beaded along tightly bundled strands of a chemical substance called deoxyribonucleic acid (DNA). These strands are known as chromosomes. Humans have 46 paired chromosomes (half inherited from each parent), with two sex chromosomes that decide gender and 44 chromosomes that dictate other factors. Certain portions of DNA are unique to each individual. DNA profiling is a way of establishing identity and is used in a variety of ways, such as finding out whether twins are fraternal or identical. DNA samples are usually obtained from blood.
Is this a perfect method?  No, but it’s a good way to get a general idea about where your ancestors were from.  Genealogical DNA tests can tell you a lot about your ancestry going back 300-500 years in time, for the most part.  They can also tell you a little bit about your ancestry going even further back.  This is why comparing your DNA to those whose families have stayed in a particular area for a long time is a fairly accurate way to perform the estimate.

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?
My daughter and I did 23andMe. Love them problem being, I was adopted and have been told all my life I have indian (Cherokee) in me. It showed nothing no indian in me. My daughters father side said they have Mohican and Italian it showed nothing for her. Is there another site that can help. I have talked with my bio family and they say my father had indian in him.
A relative of mine recently had a DNA test done. When he got the results, the ethnic groups which he was told he was a part of were just didn't add up. The family name on my grandmothers side in Germany is so rare only a few families exist with the family name. Is it possible since this DNA has never been used as a genetic marker in the passed that it could be misidentified. Basically being told your Scandinavian when you know you are German??
Below we have included both a quick comparison chart that looks at each DNA testing option side by side and a detailed breakdown of each section in that chart. We’ve covered Family Tree DNA, MyHeritage DNA, AncestryDNA and 23andMe in our comparison because these four companies are the main trusted providers of genetic genealogy tests in the current market.
Four testers took 23andMe DNA kits during testing. We received our results 32 days later, and testers were highly satisfied with the overall experience, from ease of sample collection to the thoroughness of the results. Recently, the company updated its database and increased the number of geographic regions from around 170 to more than 1,000. The updated ancestry reports are also more detailed, especially for non-European regions. 23andMe’s ancestry tests give you information split into several different reports spanning your ancestry composition, maternal and paternal haplogroups, neanderthal ancestry and DNA family. Testers particularly liked the timeline feature, which estimates when your most recent ancestor lived in each of your matched regions. 
23andMe is one of the most recognizable names in the consumer DNA testing industry. It boasts over five million users and offers five distinct ancestry reports, as well as optional relative matching. 23andMe’s ancestry testing service is our pick for the best overall DNA test because it’s easy-to-use and understand, gives you a variety of information based on your DNA sample alone, and offers an FDA approved health screening upgrade.
Our testers received notifications that our samples were received 15 days after we mailed them. The email also said that it would take approximately six to eight weeks from that point for results. It actually only took 17 days after the email to get our results notifications. From mailing our samples back to collection, all in all, was 32 days. This was slower than several other DNA services, including the speedy MyHeritage DNA, which had a 16-day turnaround.
As with traditional genealogical research, DNA testing can provide surprises so be prepared for the unexpected. You might uncover family secrets by matching with a cousin or a half-sibling that you didn’t know existed. Conversely a relation who is expected to share DNA with you might turn out not to be a genetic relative at all. In rare cases, people discover that their parents are not their biological parents. For a good overview of the ethical implications of DNA testing see the Genetic Genealogy Standards.

While DNA contains material common to all humans, some portions are unique to each individual. These portions, or regions, contain two genetic types (alleles) that are inherited from the person’s mother and father. A person’s DNA profile is made by investigating a number of these regions. In a paternity test, for example, the mother’s DNA profile is compared with the child’s to find which half was passed on by the mother. The other half of the child’s DNA is then compared with the alleged father’s DNA profile. If they don’t match, the ‘father’ is excluded, which means he isn’t the father of that child. If the DNA profiles match, the ‘father’ is not excluded - which means there is a high probability (more than 99 per cent) that he is the father. DNA tests such as this can’t offer 100 per cent proof.
Otherwise, the home-testing kits could be said to fit in with our increasingly health-conscious and, if you wish to be cynical, narcissistic times. What says you’re “special” more than finding out everything about yourself, right down to the nitty-gritty of genetics? In this way, these kits could be viewed as the latest plaything of the “worried well”. You could see how the scientific approach would appeal to the health-obsessed of all sexes and ages, your marathon runners and serious gym-goers, who take their fitness extremely seriously.
In sexual reproduction in mammals the DNA in the sperm and egg joins up so that homologous sequences are aligned with each other. This is followed by exchange of genetic information to form a new recombined chromosome which is passed on to the offspring.  Cell division then takes place and the chromosomes are duplicated in the process of DNA replication, providing each cell its own complete set of chromosomes. The double-stranded structure of DNA provides a simple mechanism for DNA replication. In this process the two strands are separated and then each strand’s complementary DNA sequence is recreated by an enzyme.