Which is all very well, but do these kits work and deliver the service they promise and what about the wider ethics and implications of home genetic testing? Is it always wise for generally under-informed, under-prepared consumers to meddle in the highly complex, nuanced arena of genetics, risking confusion, complacency or even outright panic and anxiety when confronted with ostensible “bad news” (which may not even be true)?
Consult a doctor on any health data: Cancer. Leukemia. Heart disease. Alzheimer's. There are a lot of scary afflictions out there, and your DNA testing may well indicate which ones to which you are genetically predispositioned. But the data from DNA testing exists in isolation. You should consult your doctor to explore the data from any of these tests. They'll help you determine how to implement any lifestyle changes or followup testing as a result, if it's worth doing so.

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.

A. Be aware of DNA tests advertised at this price. DNA Clinics have received calls from many anxious individuals who have had these DNA tests carried out for £59 only to realise that the test has been performed at an overseas non UK accredited laboratory. DNA Clinics most affordable test is a Peace of Mind Paternity DNA test available for £119 from www.homednapaternitytest.co.uk. Whilst this is more expensive than the £59 DNA test, you have the reassurance that all testing has been performed at Crystal Health ISO17025 accredited laboratory using strict chain of custody protocols.
Whether it’s an autosomal test, a Y-DNA test or an mtDNA test, virtually all providers use the same science. Some providers offer an ‘off the peg’ solution such as Ancestral Origins™ or AncestrybyDNA™, so if you’re interested in these you should shop around for the lowest price. Most providers offer a test that interprets and presents the results in a unique way, so if one of these catches your eye, look for examples of how the results are presented on their website before you buy.
These tests can reveal the migratory paths of your paternal and maternal ancestors after they left Africa 200,000 years ago. By studying the migratory route they took, this can help you identify the ethnic groups they may have been part of. That said, as your paternal line is your father’s father’s father etc., and as your maternal line is your mother’s mother’s mother etc.; your paternal and maternal ancestors represent a smaller and smaller proportion of your ancestry the further back you go (just one sixteenth of your total ancestry five generations ago). Therefore, tracing your migratory paths back thousands of years may provide insights, but they’re a poor means of exploring your ethnic mix.
The core feature of all ethnicity DNA tests is to show you a breakdown of the ethnic groups who have contributed to your autosomal DNA, normally as a list, pie chart, and/or map in an online account. It’s understood that these tests give you a picture of your ethnic heritage from the past five to six generations, and this is because the number of your ancestors increases exponentially the further back you go.

Getting the most out of your AncestryDNA results requires a bit of work, as the DNA test works best in concert with the site’s other available resources. You can use the DNA service without creating a family tree, though the results are much less interesting. Ancestry uses information gleaned from its user’s DNA and family trees to create compelling stories about your family’s recent history and migrations. Testers with European roots could trace their family’s movements across the Atlantic and see what stops they made on their way across the U.S.
MyHeritage DNA is the newest kid on the block and, while their database is still growing, it is comprised of people who have tested from all of the other three testing companies (this is thanks to their free DNA upload offer). In addition to this, they have shown a clear commitment to concerns and requests by their users by promising to provide advanced tools in the future and by creating an open and optional consent policy for use of DNA data. They also offer the ability to tie in with a large database of family trees and records. We think this test has a lot of promise if they continue to respond in this positive way to users.
Still, it is fun see a visual and numerical representation of where your ancestors came from (generally speaking) and, although there are those who swear by one company or the other, all of these testing companies do a fairly decent job of giving you a report you can enjoy and use in your research. FTNDA recently updated to the much anticipated MyOrigins 2.0 and MyHeritage DNA just updated to their improved 42 population Ethnicity Estimate and offers a nicely detailed report.
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.