Frequently Asked Questions

Frequently Asked Questions


What species do you test?
We routinely test mouse, rat, and zebrafish samples, but we can accept certain other species. Please contact us to inquire.
How do I submit samples?
Create an account to be able to submit sample requests online and receive account and request summaries.  If you will not be submitting online, simply download and submit a completed genotyping request form with your samples.  Email us to let us know they are on the way. For complete details, see the sample submission page.
Can samples be sent at room temperature or should I freeze them?
Yes, samples can be sent at room temperature.  In fact, we prefer samples be collected and shipped at room temperature.   Samples that are frozen and then are allowed to thaw will experience significant degradation.  If you absolutely must freeze the samples, please make sure they remain frozen at all times, including during transit.  In the picture below,  samples 53 54 and 55 had been previously frozen and allowed to thaw prior to shipping.  Samples 52 and 116 demonstrate intact genomic DNA.

DNA quality

I have a strain that needs to remain private, will it be kept private?
Yes, strains that added to your account are only visible to you.
Do you accept samples from institutions outside the United States?
Yes, we do.  Please see our guidance on international shipping.
Do I need to send known controls with every order?
Known controls are only required for validation of new assays. We automatically save control samples at our facility, so you do not need to send them with every order.


How much to do you charge for creating new assays?
For new assays we offer our design expertise at NO CHARGE if known controls can be provided, or $295 without known controls.
I have a strain that is not on your lists, how do I arrange for testing of these mice?
If the strain is commercially available, send us an email and we will look into it. We will let you know within 24 hours if we can do the testing. We may already have all the necessary primers, but not have the strain built into our system. If the strain is not commercially available, but can be detected using the targets we have available, you can create your own strains in your account and provide us the available targets. If we do not have the necessary targets/alleles available, there is a link in your account to a submission page for submitting new targets for assay designs. We offer assay designs free of charge.
What are Hydrolysis Probes?
Hydrolysis probes are probes that are hydrolyzed during the amplification process, releasing the fluorophores to allow detection of amplified products.  They offer the advantage of an extra layer of specificity for target detection.
What is SYBR?
SYBR green is an intercalating dye that allows real time detection of product amplification. When combined with melt curve analysis it provides a higher level of specificity.


When can I expect my results?
We guarantee delivery of your results within 2 business days of receiving your samples or your testing is free. Validation of new assays will take longer time. Additional control material may be requested.
What will my results look like?
Please view our sample report page to see our reporting layout.  Results are sent by email as they are completed.  In addition, this file will be in your account, available for download at any time.
How do I interpret my results?
We use the following terminology to describe sample results on reports.

  • Wild = (Wild-type) for both transgenic and KO (knock-outs) and KI (knock-ins), these mice lack the mutation that is being tested for by the assay.
  • Hemi = (Hemizygous) for transgenics, these samples have the transgene on one of the pairs of homologous chromosomes but lack the transgene on the other.
  • Het = (Heterozygous) for KO and KI, these samples have the mutation on one of the pairs of homologous chromosomes and have wild type sequence on the other.
  • Hom = (Homozygous) for both transgenic and KO and KI, these samples have the mutation/transgene on both of the homologous chromosomes.

For transgenics, if the assay is not a probe-based zygosity test, but is instead our basic presence/absence assay, we will report the sample as Hemi. This is equivalent to saying present and is NOT a zygosity call.

Why are all of the melting temperatures the same for one or more of my targets?
The LC480 software can be very poor at autocalling the location and number of peaks.  Below is an example of an assay which was autocalled.  It is important to understand that the software designates samples with two peaks as green lines and ones with one peak as red lines.  Therefore, almost every sample is miscalled by the software.


Fixing these miscalls is easy using the software by selecting all of the samples in a peak and imposing a melting temperature for the group.  This will give all of the samples the same melt temperature.  Below is the corrected version of the above graph.

For separated assays, this same technique is used to remove samples that did not amplify, but upon which the software imposed peaks on flat lines.

What is the difference between separated and multiplexed assays?
Multiplexed assays use multiple sets of primers in one tube to amplify both the wild type and the mutant targets for the method.  The biggest impact on the appearance of your results is that the tm for single peaks (EITHER Wild or Homozygous mutant) will be represented as tm1.  Only Heterozygous samples will have a tm2.

Separated assays will utilize two wells for each method.  One tube will have only wild type primers and the other tube will have only mutant primers.  On the report the results for the two tubes will be separated into two heavily lined boxes.  As a result the data will look different.  Wild type and Heterozygous samples will have a tm1.  Homozygous mutant and Heterozygous samples will have a tm2.


Can I pay for my testing with a credit card?
Yes, we can accept credit card payments directly or via PayPal.  We will send credit card payment information by email along with your invoice.  Simply click on the link and follow the instructions.

About GTCA

Why the name GTCA?
The GenoTyping Center of America (GTCA) was coined by one of the founders.  It informs you of what we do (genotyping), shares the same acronym with DNA (Guanine, Thymine, Cytosine, and Adenine), and speaks to where we started.