Experts in testing stock homogeneity by DNA barcoding

Stock homogeneity testing service for species used in ecotoxicology

The use of a morphospecies which may actually be complex of cryptic species, or even species mixing in laboratory stocks, is a serious problem for the reliability of the ecotoxicological tests. Even if they show similar responses to toxicants, the presence of two species within the same laboratory culture can result in the production of sterile hybrids, which will bias the outcome of any reproduction test.

Our stock homogeneity testing service verifies that all the specimens in a laboratory stock belong to the same species, or even to the same genetic lineage. As a norm we analyse by DNA barcoding 91 specimens per stock. This allows us to detect a contaminating species occurring at a minimum frequency of 5 % with a probability of 99 % in a cost-effective way. At the same time, you can precisely document the species or genetic strain being used in your tests. We strongly advise carrying out a test of stock homogeneity every time a new stock is acquired or used to initiate new cultures.

The graph shows how DNA barcoding can be used to detect contaminations in ecotoxicology cultures. The workflow includes the following steps: DNA isolation from a number of specimens from the culture, PCR amplification, sequencing, and bioinformatic analysis to identify the matching species for each of the samples analysed.

Step 1

We isolate DNA from your specimens.

Step 2

We amplify the genomic region of interest (the DNA barcode) using universal or in-house-developed primer pairs.

Step 3

We sequence the PCR products in both directions.

Step 4

We analyse the electropherograms obtained and compare the resulting sequences against reference databases to find the matching species.

Step 5

We evaluate the occurrence of contamination and its extent in the stock analysed.

What you receive

A stock homogeneity certificate.
A report with a summary of the methods followed.
The raw electropherogram files.
Your manually-edited sequences in FASTA format. If you require additional analyses, please let us know and we will do our best to meet your needs.
At no additional cost, our project specialists will be available to you after project delivery. We offer up to five 60-min sessions per project, depending on the project size.

What we need

Your tissue samples appropriately preserved depending on the sample type (ethanol, silica gel, frozen, or another suitable preservation method). If required, we provide sampling kits and sampling collection guidelines to ensure that your samples arrive at our lab in optimal conditions.

Contact us for further information and pricing