On FishFloor UCL, Gareth Powell would be the best person to ask for a live demonstration.
Technique originally published by Kosuta et al (2018) – video protocol:
https://www.jove.com/v/58024/high-throughput-dna-extraction-genotyping-3dpf-zebrafish-larvae-fin
Kosuta, C., et al. (2018). “High-throughput DNA Extraction and Genotyping of 3dpf Zebrafish Larvae by Fin Clipping.” Journal of Visualized Experiments(136).
This method can be used to genotype larvae before they are 5 dpf. This way, only growing up larvae with the desired genotype (e.g., when generating a new line). This reduces the number of fish used and fulfils the 3R aims of the Home Office.
It is a time-consuming process. Therefore, it is advised that you first ensure that your parent fish does have the mutation in their germ line. To do this, first take a cohort of embryos, extract their DNA and sequence it, or do a headloop PCR, to check. This adds time to an already laborious technique.
The Fish Facility does not currently give you enough time to screen the animals before they are put into the nursery.
The first lab to use this technique have grown these fish to adulthood and bred them with no issues - that has not been achieved at UCL though so it is likely there will be a drop off in survival
It would be a good idea to try this first with raising a new generation of a line that we know doesn’t have any problems with viability in the nursery, just to check that the tail clipping doesn’t introduce any additional mortality in our system. Other labs might not have experienced problems, but our systems and our regulations are different.
It is worth verifying that it is included in your project license too, before you go ahead and use the procedure.