Sampling packs
When you create an account on the website and request a sampling pack, we post an envelope containing:
- instructions for collecting honey samples straight from the comb,
- 3 x labelled sampling tubes,
- a resealable plastic bag,
- a padded Freepost return envelope.
Your sampling pack should look like this when it arrives:
If anything is missing, please email honey@ceh.ac.uk.
Collecting honey samples
When your sampling pack arrives, and your hive is producing honey, please follow the instructions in the sampling pack on how to collect your three honey samples straight from the comb, or check out this video:
If you have collected your samples very carefully and they do not contain wax, please leave us a note in your return envelope. If you have a flow hive, please indicate this in your online questionnaire under “hive type”. If samples do not contain wax we will assume they are extracted honey, which is not suitable for the scheme and will not be including for pollen analysis.
This is because extracted honey:
- may have been collected from multiple hives so the hive data you have provided in your online questionnaire is less likely to be accurate,
- is more likely to have been produced by the bees across multiple timepoints so the date you collected the sample is less likely to relate to when the honey was produced,
- is often filtered, which results in removal of the pollen grains we are extracting DNA from and means the sample is more likely to fail the pollen analysis lab workflow.
Sample processing
When your honey samples arrive at UKCEH they are logged in our system and assigned a unique identifier so that no one’s personal data is visible to those processing the samples. At this point you will receive an email update to say your samples have arrived with us. One sample is placed in our honey archive, one sample is sent for pesticide analysis and one sample is taken forward for pollen analysis.
Pollen analysis
This diagram gives an overview of our pollen analysis workflow:
If you are interested to know about this process in greater detail, check out our video:
Briefly, a small amount of honey is taken from the sample marked for pollen analysis and spread on a refractometer to determine the sugar and water content. These values will be added to our online system and beekeepers will receive an email update to say these results are available.
Next, we weigh 15 g of honey into a fresh tube, top it up with water and heat for an hour until the honey has dissolved. This mixture is added to a vacuum pump with filter paper on top – when the vacuum is applied, the liquid is drawn through the filter paper leaving the pollen grains on top.
This filter paper is kept frozen until DNA extraction. As pollen grains are designed to be resilient to desiccation in the environment we use both chemical and mechanical approaches to break open the pollen grains and release the DNA. We purify this DNA – to remove cell components that would damage the DNA or inhibit the next step – and return it to the freezer until we are ready to amplify it.
The DNA extraction is a collection of all DNA released from the pollen grain – as well as microbes that might have been in the honey or on the pollen. For the scheme, we are only interested in the pollen DNA and only in a short region of it. We perform a PCR on the DNA extraction to isolate the DNA region we are interested in and to create many copies of this region so we can sequence it. Whilst creating these copies, each end of DNA region is affixed with a tag. The pairing of tags is unique to each honey sample and allows the DNA regions to be assigned to the sample it came from after sequencing.
Once 384 honey samples have been filtered, DNA extracted and PCR amplified the DNA is pooled together into one sample and sequenced. The sequencer produces several millions of DNA sequence, which are assigned to the sample they originated from by the tag combination at each end (“demultiplexing”). These sequences are then matched against a comprehensive database of plant DNA, to find out what species of plant the pollen belonged to.
When we have this information, it is checked over by a plant expert at UKCEH to ensure the species detected are sensible for the UK landscape before being made available to beekeepers. At this point beekeepers will receive an email update to say their pollen data is available.
We analyse approximately 1,000 honey samples each year so pollen data can take up to 12 months to be made available to beekeepers. We appreciate your patience in the meantime and thank you for contributing data to a long-term monitoring scheme aimed at understanding the health of the UK countryside.
Pesticide analysis
From 2019, 2020 and 2021 we have been assessing pesticides for Defra in 100 honey samples each year. This work will continue for 2022 although these samples are only now being processed. From these honey samples with use Liquid Chromatography–Mass Spectrometry to quantify residues of 89 pesticides including insecticides (n=23), fungicides (n=44) and herbicides (n=22).
Each year the 100 honey samples are split between:
- 40 samples collected in May from arable agriculture & horticultural landscapes
- 40 samples collected in August from arable agriculture & horticultural landscapes
- 10 samples collected from urban landscapes
- 10 samples collected from semi-natural landscapes
These maps show where samples sent for pesticide analysis in 2019, 2020 and 2021 were collected from:
