How do I know if there is a mixture of two or more human cell lines present in my sample?

If a mixture of more than one human cell line is present there will be more than two peaks at several loci in your STR DNA profile report/data.  The peak height value is indicative of the signal strength of that allele, which theoretically should have a direct relationship to the amount of DNA in the sample.  Hence, in a mixture of human cell lines where some of the peaks at a locus are significantly higher than others, the larger peaks would belong to the cell line that was the major component of the mixture.  The smaller peaks would then belong to the minor component of the mixture. 

Please be aware that a mixture of two or more cell lines can look very similar to "genetic instability" in a cell line - where subpopulations of the genuine cell line exist which have a different STR DNA profile at some genetic loci due to genetic instability which is inherent to cancer cell lines.  It is therefore crucial that a trained DNA analyst helps to interpret the electropherogram (peak) data in these difficult cases to eliminate a possibility of a mixture as the cause of the additional alleles.  We are always here to help, so don't hesitate to contact us if you have questions about your data.

How do I know which report option to choose for my specific needs? 

All of our report options offer the same high quality STR profiling test (we use PowerPlex 16HS), the difference and what determines the price is the report format.  Please note, the electropherogram (peak) data, included with each test, is a useful tool for monitoring your cell line's identity, especially when you have your cell line tested for authentication as the passage number increases over time.

Option #1 is our most cost efficient option and is perfect for routine quality control testing of your human cell line or other samples.  

What you get:

  • Excel spreadsheet of the ANALYZED STR DNA profiles of all cell lines submitted in one batch
  • Peak data for EACH submitted specimen

Option #2 is our first "report" option signed by a Laboratory Director.  This option is typically selected when a formal signed report is needed for EACH cell line but when the researcher needs a more cost efficient report versus Option #3 or #4.

What you get:

  • Analyzed STR DNA profile of your submitted cell line in a formal signed report (no reference profile comparison) - each submitted sample will have an individual report
  •  Peak data for EACH submitted specimen

Option #3 is the most comprehensive "report" option that we offer and it is signed by a Laboratory Director. 

What you get:

  • Formal signed report that includes analyzed STR DNA profile of your submitted cell line side-by-side with the KNOWN reference STR profile for that cell line (e.g. from ATCC, etc)
  • Comprehensive interpretation that includes percent match and percent identity calculations which indicate how closely your submitted cell line matches the known reference cell line
  • Peak data for EACH submitted specimen

This report will clearly indicate if your cell line is authenticated or if it is misidentified.

Option #4 is a "report" option signed by a Laboratory Director. This option is used most often for researchers who submit two specimens for comparison to EACH OTHER; it is useful for labs creating in-house cell lines (e.g., compare patient sample to low passage stock of established primary,cancer or stem cell line) or when testing xenografts from patient tissue.
What you get:

  • Formal signed report that includes the analyzed STR DNA profile of your submitted "questioned" specimen side-by-side with the analyzed STR DNA profile of the submitted "reference" specimen
  • Comprehensive interpretation that includes percent match and percent identity calculations which indicate how closely your submitted specimen matches the submitted reference specimen  
  • Peak data​ for BOTH specimens

Have questions or would you like to order a test? CLICK HERE

Do I need to authenticate my cell line if it was purchased from a repository?

If your cell line was purchased from a repository, an authentication report may have been included with your purchase. 

However, cell lines should be continually authenticated after purchase. It is recommended that cell lines be validated every 1-2 months during active growth.  In addition, many journals now have guidelines for cell line authentication testing prior to publication. 

Contamination and misidentification can happen in any lab; it is therefore crucial to authenticate your cell cultures periodically so that you are sure you are working with the genuine cell lines as your experiments progress.​​

Why should I trust Genetica DNA Laboratories with my cell line?

Genetica DNA Laboratories, a  LabCorp brand, has over 25 years of experience in human DNA identification.  The DNA laboratory provides high quality DNA tests including parentage, family relationship, and human DNA identity tests, as well as research services such as cell line authentication, MSI testing and mycoplasma contamination detection testing.  Check out the accreditations and other qualifications page:


Frequently Asked Questions

Do you only offer human cell line authentication testing?  What about mouse cell line authentication?

There is currently no universally-accepted written standard or publically available reference database for mouse cell line authentication testing.  There is a mouse cell line authentication consortium currently in session to develop a testing method and written standard; an effort organized by NIST and ATCC in the USA and supported by labs such as Genetica.  We expect to be able to offer this test commercially once the standard is formally approved and available for public purchase.

Some of our clients submit their non-human cell lines to check to see if they are contaminated with any HUMAN cell lines; we have processed samples for this purpose and have found instances of cross-contamination between human and non-human samples.  In addition, we now include a MOUSE marker in our human cell line authentication test to detect the presence of mouse DNA, providing an extra piece of information about your submitted cell line.

Can cross-contamination of cell lines or cell line misidentification adversely affect my research data?

Yes!  There are researchers who have lost years of work to problems such as cell line cross-contamination or misidentification.  On August 15, 2010, the authors of a paper originally published on April 15, 2005, retracted their article stating:

  • "Upon review of the data published in this article, the authors have been unable to reproduce some of the reported spontaneous transformation events and suspect the phenomenon is due to a cross-contamination artifact."[5]

The paper, titled "Spontaneous Human Adult Stem Cell Transformation" [6], included research on human stem cells which were reported to "transform" into cancer-like cells.  The 2005 paper was cited many times by other researchers who, like the authors, were astounded at the possibility that stem cells could be "cancer-like".  The contamination was later found to be due to HT1080 cells, a cancer cell line that overgrew the stem cell culture.

Check out our references page for more case studies in cell line misidentification.​​

Why is it important to get your cell line authenticated? 

The validity of research data relies heavily on the identity of the cell line used in testing.  According to the American Type Culture Collection (ATCC) Standards Development Organization Workgroup (SDO) ASN-0002 [4], only 33% of researchers test the authenticity of their cell lines.  Cell line authentication puts your mind at ease about all the hard work and time you have put into your research. Retractions hurt the reputation of the researcher and the research institution that supports the research.

1-800-IDENTITY®  (433-6848)      1-513-985-9777 International

I have my cell line authentication results, now what do I do?

The data you receive from Genetica can be used to compare your submitted sample's STR profile to the STR profile of the reference cell line sample (either a repository cell line or patient sample).  All of the STR DNA loci that we tested are used in the repository reference databases so you will be able to compare the STR profile from our test with any of those databases.  If you purchased your cell line from a repository, then the reference profile will be available through their website (Click here for links to the most common cell line repository reference databases). 

If the STR DNA profile of your submitted cell line matches the known reference cell line's STR DNA profile at every overlapping genetic site, then your submitted cell line is "authenticated".  If there are differences present, it could mean misidentification, mislabeling, contamination by another cell line or genetic instability.  A percent match of 80% or above is considered "authenticated" [4], anything below that threshold should be regarded with suspicion.  If the tested cell line has been contaminated or misidentified, additional authentication testing should be done on earlier passages of that cell line to identify where the problem originated, or a new cell line stock should be obtained from a reputable source.  Any research experiments done with a contaminated or misidentified cell line may have to be performed again with a genuine stock before publishing or moving forward with your research. 

Still having trouble with your results? We are here to help!  Contact your Genetica lab representative and ask as many questions as you need to.

My lab is not in the United States, do you accept samples for cell line authentication and other services from other countries?

Absolutely!  We currently accept samples from around the world, including, but not limited to England, Australia, Italy, Singapore, India, Hong Kong, Canada, Argentina, Mexico, Norway, The Netherlands, Scotland, South Africa, Spain, Chile, and Malaysia.  The best option for sending samples overseas is to extract and quantitate the DNA from your cell line sample(s) in your own laboratory (or send a DRIED cell pellet).  The extracted DNA or dried cell pellet from your cell line samples do NOT need to be on ice; shipping at ambient temperature is sufficient and causes no problems with the cell line authentication testing process.  Sending a bulky dry ice package internationally could be expensive and potential shipping delays could damage the samples.  If you prefer to send fresh/frozen cell pellets - please contact us for the best option for your specific needs. 

Which journals or funding agencies have guidelines for cell line authentication prior to publication or for grant applications?

Visit our "Journal & NIH Guidelines" page for more information

Cell Line Authentication & Research Services 

Is there a current list of cross-contaminated and misidentified human cell lines?

Yes!  The International Cell Line Authentication Committee (ICLAC) maintains an up-to-date list of all human cell lines that are known to be misidentified.  Check your cell lines today to see if they are on this list.

Will the cell line authentication results I get from Genetica DNA Laboratories be accepted by the journals?

We are listed as a service provider for cell line authentication testing on several different websites, including the American Association for Cancer Research (AACR) website.  We have been in the human DNA identification business for over 20 years and the lab has the accreditations and technical experience to support these services at the highest level.  Many of our clients have already published in various reputable journals using our cell line authentication testing results - ask us for references that include our tests!