Mellissa attended a residency at the Eden Project as artist in residence at the Invisible Worlds Lab, where she began a new line of research, unearthing the fascinating stories that lie within soil, experimenting with synthetic and natural dyes and developing ways in which to visualise the invisible world of plants. With guidance from Eden’s horticultural specialists, Mellissa investigated the plant life of the Biomes and botanical cells by studying soil and plant tissue samples with collaborator Professor Mark Clements.


Mellissa experimented by making her own dyes/stains which were extracted from plants.  There were used to visualise cellular structures of plants and also to explore in more detail the microbes within soil and plant tissue. She also conducted experiments to isolate and grow different fungi from decaying wood samples as well as soil, to look at the diverse morphologies of the organisms that grew. Together with Prof. Clements, they set up competition experiments between the different fungi to study their interactions, with the hope of mycelial combat (‘fungal wars!’) on the plate and under the microscope.

Mellissa Fisher’s work with the Eden Project began with the exhibition The Invisible You: The Human Microbiome, where she is currently exhibiting the project Microbial Me, an agar sculpture of the artist’s face with bacteria from Mellissa covering the surface of the agar.  This living sculpture has been growing in the space for over three years.

RESIDENCY DURATION 1st - 12th August 2018

Returning to the Eden Project was incredible and seeing the way the project Microbial Me has evolved over the last 3 years was fascinating. It was also incredible to see the new Invisible Worlds Lab built in the Core building with all the interactive art works, and the breath taking centre piece Infinity Blue by Studio Swine. It was the perfect environment to inspire my current line of enquiry into the plant world whilst also allowing me to communicate my findings with the public who visited (apparently 10K people per day visit in August). 


My research began by looking into a section of the Eden Project garden where all the plants that grow are used to create dyes, these include: Bloodroot, Canadian Goldenrod, Chinese Indigo, Dyer's Greenweed, Horesfly Weed, Woad, Heather, Stinging nettle, Madder, Daffodil, Oregon Grape, Staghorn Sumac, Lady's Bedstraw, Rubarb, Impatiens Tinctoria, Weld and Pokeweed. I collected samples from each plant that was growing this time of year and set up agar plate experiments by immersing the plant samples into agar and then incubating to see what microbes or fungi grew a few days later. I worked closely with lab technician Sophie Holden who assisted me with setting up the experiments as well as sharing her knowledge of biology.

I was keen to collaborate internally with staff at Eden and one in particular, Carla Wentink, (story teller) who has worked at Eden for 16 years. Carla visited me in the lab to share her knowledge about natural dyes extracted from plants and also her knowledge from dyeing wools and fabrics in her spare time. She came into the lab with samples of hand spun wool that she dyed with Madder, Indigo and Woad. Carla also showed me the physical specimens she had of Madder Root and Oak Apple which she explained the process of producing the dye from each specimen.

The microscope I was using at the Eden lab, Zeiss Axio zoom V16, where the majority of my images have come from during this residency. Both Carla and I looked at her hand spun and dyed wool samples, this exchange has inspired us both in different ways; myself with natural dye plant research and Carla who has been shown a different perspective of making natural dyes.  My purpose of understanding this process was to make my own dyes in an attempt to stain the internal structures of plants. This resulted in Carla kindly giving me concentrate of Chinese Indigo, Madder and Weld to experiment with. 

The first weekend of the residency my collaborator Professor Mark Clements, from Middlesex University, joined me to run experiments to stain plant cells with synthetic dyes and natural dyes I had made a few days before. We also looked at the results from my first experiments when I immersed plant specimens into agar plate to see what microbes would grow from each plant sample. We also perfected our ability to perform epidermal leaf peels which are a monolayer cells taken from the leaf. We stained these leaf peels with both natural and synthetic dyes. We also used the Gram staining protocol to see whether the bacteria grown from the first set of experiments were Gram positive or negative which helped us identify the growth as likely to be Bacillus subtilis.

In another set of experiments we also put cuttings of Canadian Goldenrod in to 3 natural dyes and 3 synthetic dyes so that the plants could naturally take up the dyes through the process of transpiration. 1 of each natural and synthetic dye was toxic as observed from the way Canadian Goldenrod cuttings showed signs of wilting whilst other samples were thriving. We also tested whether the natural dyes would dye the stems of the plants, but over the duration of the experiment we found that the synthetic dyes spread and dyed the stems much quicker and more intensely than the natural dyes. Images below show how the synthetic dye made it through to the veins in the leaves and the cross section of the stem shows how much of the cells taken up the dye over a short duration.

Experiment duration: 12 hours.


From my first set of experiments where I placed samples of dye plants in agar to look the what microbes would grow we found that Impatiens tinctoria (Balsaminaceae or commonly known as Balsam) was the most interesting specimen. All the other plates showed growth of fungi or bacteria from the plant samples, but the plate with Balsam showed a yellow dye with no growth of fungi or bacteria. Prof. Clements and I isolated each different type of fungi and bacteria from the original experiments and applied them to each plate with a sample of Balsam (see images above). The antimicrobial properties are clearly shown in the images, were no microbial growth was observed in the areas of the plate where the leaf samples had secreted a yellow dye.  It is likely that this yellow pigment is a natural molecule produced by the plant to protect it from bacterial and fungal diseases.

Balsam is also used in traditional medicine: Roots can be made into a drink to treat abdominal pains, a paste can be made and applied to the skin as a beauty treatment and it toughens the skin to control fungal infections, the stem can be chewed to treat mouth and throat diseases. It has also been show to have anti-fungal properties against common infections such as athletes foot.  This research of the literature confirmed our observations from the agar plate experiments.


When the natural dyes were used to stain the leaf peels I was amazed at how a dark red (Madder) and green (Eucalyptus) dye could create stain the cells a bright pink colour revealing in internal cell structures and staining the walls of the cells a silver colour. I was also interested in how the natural and synthetic dyes would worked together and found that the Toludine Blue was taken up only by specific cells in the monolayer whereas Saffrinin O specifically stained the stomata which regulate the amount of water taken up by plants.


The synthetic dyes we used are not commonly used for plant biology.  For example, Alician Blue is used for staining the bone, Safranin O is used to stain embryos and Toluidine Blue is used to stain DNA nucleus of cells.  

LEFT TO RIGHT: Safranin O & Toluidine Blue - Madder & Eucalyptus 


Dr Rachel Warmington, Plant Pathologist at Eden, took me around the Rain Forest Biome to allow me to take samples to study in the lab following bio containment protocols.


Whilst being shown around the Rain Forest I was attracted to leaves which had a waxy backing, as I wanted to practice the epidermal leaf peel method to see the differences the plants in the biome had to regular outdoor plants. I was also looking for brightly coloured leaves to see whether that colour would translate into the cellular structures of the epidermal peel, this was the case for a few of the specimens, one of which I did not use any dyes for was Tradescantia Zebrina

Tradescantia zebrina (commonly known as Inchplant) is native to eastern Mexico on the Gulf Coast region. It is a weed that covers many areas including the rain forest and warmer climates such as eastern Australia. It has been reported to be an invasive species which spread across damp areas, however it is also a common houseplant. 

Caladium Red Flash stained with synthetic and natural dyes.


Sanchezia Speaosa & Coleus Wizard Mix

Whilst studying the rain forest plant samples, I practiced the epidermal leaf peel protocol and used the Zeiss microscope to gain a different perspective of each sample. All the samples from the rain forest were hardy plants that had less stomata and more complex cell structures. I am currently in conversations with Plant Biologists to understand the differences in more depth as well as showing my experiments with natural and synthetic dyes as each dye highlights an aspect of the cellular structures that differs from one plant to the other.  I also  repeated my first experiment of immersing the rain forest plant samples into agar plates to see whether the fungi/bacteria growth was more or less than the more conventional plant samples (see images below).



Prof. Clements and also I extracted pollen from a hibiscus (Hibiscus fragilis) flower from the rain forest biome. The grainy images above are taken on my iPhone SE through a 40X magnification microscope and the images below are taken on the Zeiss Zoom v16 microscope. We wanted to study the anther and stamens of flowers in more detail.  This will form the basis of future research into pollination and reproduction of plants.

LEFT TO RIGHT: Lily Stigma ZEISS ZOOM v16 - Lily Stigma Compound Microscope 40X


In another set of experiments that we planned for the residency we explored how soil bacteria and fungal affect the germination and growth of seeds. We took samples of soil from where the natural dye plants grew in the gardens.  One sample was autoclave to sterilise the soil to kill all bacteria and fungi whereas the other sample was left untreated.  We then sowed the two soil samples with Sorrel seeds because of the natural dyeing properties as well as wanting to have seeds which would germinate and grow quickly. The seeds began to germinate within 24 hours which was faster than Prof. Clements & I expected. The images below show the sterile soil on the left and non-sterile on the right. We observed that the sterile soil seeds grew less well and at first glance we assumed the hairy appearance was fungi which had contaminated the seeds.  

However on closer inspection (see microscopic images) we realised there were root hairs which are used by the seed when germinating as the root hairs cling onto the soil where the nutrients are, to enable the seedlings to thrive and grow.  The seeds growing in sterile soil produced many more root hairs suggesting that they were searching for additional nutrients which would normally be released by bacteria and fungi in the soil. At the end of the residency we also set up larger scale competition experiments in conical flask ecosystems.



Photos above taken on iPhone SE through compound microscope at 40X  and photos below taken on Zeiss Axio zoom V16


The last weekend of the residency consisted of running soil experiments but also to observe the results from agar plates inoculated with lichen.. I looked into how many different types of bacterial and fungal growth appeared after 2 days and focused on each one (photos below taken on Zeiss microscope). 

Looking back at the residency it is interesting how Modified Madder dye plant started a line of enquiry into the natural dyeing process leading onto more in depth research into different plant specimens, soil experiments, isolation of bacteria and fungi on agar plates, exploration into the anti-fungal properties of plant samples and observing the difference between the macro and micro structure of plants grown in rainforest and temperate environments. Both Professor Clements and I spent time with the public at the Eden Project, speaking about Microbial Me, as well as Microbial Michael, and explaining our research over the duration of the residency with a final talk and film screening of 'The Making of Microbial Michael' & 'Michael Mosely vs. The Superbugs' which aired on BBC4 in May 2017. 


The next stages of this project are to explore and optimise the use of other synthetic dyes and to study and understand the cellular structures of dye plants such as Madder, uncovering the interesting histories behind how these curious plants have been used. 

Special thanks to Arts Council England, Eden Project, Professor Mark Clements, Celine Holman, Dr Jo Elworthy, Sophie Holden, Chris Bisson, Carla Wentink, Dr Rachel Warmington & Gabriella Gilkes. 

© Mellissa Fisher 2015-2020

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