Single molecule fluorescent image of a human T lymphocyte (also called a T cell) in which each molecule is localised with a precision of 2-4 nm.

“With our new single molecule microscope, we can now measure distances between molecules in intact immune cells on the biologically relevant scale.”

More than 30 years after the discovery of the T cell receptor, we still do not know how signalling begins. It is important that we work out how antigen binding initiates intracellular signalling because these signals shape the resulting immune response. With new super-resolution fluorescence microscopy and single molecule imaging approaches, we aim to map the molecular level while retaining the spatial organisation of intact cells. We are developing new instruments, new analysis methods and new molecular biology tools in an interdisciplinary research program that spans physics, chemistry, mathematics and biology.



Super-resolution fluorescence microscopy promises the opportunity to place single molecules and multi-molecular complexes in the cellular context in the cellular context and in turn understand how molecular organisation of cells leads to cellular outcome. A key question in cellular immunology is how antigen recognition leads to intracellular signalling on which T cell fate decisions are based. The T cell signalling field is stymied as we do not understand how engagement of the T cell receptor (TCR) on the extracellular side initiates phosphorylation of the constitutively associated CD3 dimers on the intracellular side. Further, it is not known how diverse signalling outcomes are encoded by a common TCR-CD3 signalling transduction process. We hypothesise that the spatial organisations are key to signal initiation, integration of signals from multiple receptor, and the regulation of a highly plastic signalling network.



Science without sight: bringing medical discovery to low vision community

Professors Jamie Rossjohn, Kat Gaus and the scientists at Single Molecule Science at UNSW organised and participated in an event in Sydney where the blind and low vision community experienced scientific and medical discovery through shapes, textures, sounds, spoken word, and even smells.

Rapid advances in science and technology – from AI, screen reading software and image recognition devices – has made the world a more inclusive place for people with limited vision.

But for people with impaired vision or blindness, access to the wonder and discovery behind science has been far more elusive.

Visitors explored breakthroughs in the understanding of the AIDS virus (HIV) using tactile and audio displays and models representing developments in understanding our immune system and how this has led to more advanced cancer treatments.

The event included models of the biology of the eye, tactile models of cells, bacteria and viruses that will explain infectious diseases and a lab experience will guide participants through using real lab tools.


  1. Identify subunits and subunit arrangements of protein complexes in intact cells, exploiting the photophyiscal properties of fluorophores for molecular counting.
  2. Link protein localisation and spatial organisations to function, distinguishing signalling from non-signalling molecules and determine the environmental factors.
  3. Combining biochemical assays with single molecule imaging to establish a conceptual and theoretical framework of signal integration at the receptor level.
  4. Map signalling networks by developing new statistical analysis for single molecule data that reveals the information flow in intracellular signalling networks.
  5. Disseminating microscopy hardware and software. To make a lasting impact on the scientific community and connect with
    end-users, we are not just developing novel microscope hardware and software but also developing avenues to cost efficiently replicate and disseminate our approaches. For example, we are exploring how 3-D printing could aid in the prototyping of
    hardware and collaborating with MASSIVE to develop approaches for handling and processing large imaging-based data.

“We know how important it is to be able to communicate science to the public. Being able to participate in an initiative like this, where we were able to reach people we might otherwise miss, was so important for my group. It was such an interesting process to try and work out how to make sure our science was accessible to everyone,” said Professor Kat Gaus.

Examining the theme of the building blocks of life, presenters and researchers from the School of Medical Sciences, School of Physics, the Centre for Eye Health, the Museum of Human Disease, and Monash Biomedicine Discovery Institute also explained their research on disease agents and the structure of atoms, molecules, cells, tissues, or organs.

Sensory Scientific Exhibition & Discovery Day is supported by UNSW Disability Innovation Institute, Museum of Human Disease and the ARC Centre of Excellence in Advanced Molecular Imaging.
The Sensory Science Discovery Day was first held in Melbourne with Imaging CoE Chief Investigator Professor Jamie Rossjohn, to read more about this initiative see page 56, Communicating our Science.


The Sensory Science Discovery Day was first held in Melbourne with Imaging CoE Chief Investigator Professor Jamie Rossjohn, to read more about this initiative see page 56, Communicating our Science.

Originally published:


Photo of activity demonstrating research concepts in immune memory and recognition

6 December 2019 – Sensory Scientific Exhibition and Discovery Day

James Halstead (above top) and Jesse Goyette (above), both Postdocs from the Gaus Group designed and made their own activities to demonstrate their research concepts in immune memory and recognition.


Kat Gaus honoured with International Science and Technology Award

In a mark of her contribution to the research community, this year, UNSW’s Scienta Professor Kat Gaus was named as a laureate of the prestigious Khwarizmi International Award.

Kat received her award from his Excellency, the president of the Islamic Republic of Iran during the annual awards ceremony, Professor Gaus travelled to Tehran in February.

“This recognition is a real honour, and it’s great to see science being recognised beyond boarders, cultures and languages,” says Professor Gaus of her award from the Iranian Ministry of Science and Technology.Professor Gaus was awarded the prize for her achievements in single molecule imaging to visualise how T cells initiate an immune response. A major research focus in Professor Gaus’ research group is the molecular signals that determine whether or not a T cell becomes activated when it encounters foreign material.

Gaus’ work has been long recognised for its outstanding contribution to science, she was previously named as one of UNSW’s 15 Women Changing Our World. Along with her work with the Imaging CoE, Gaus established the EMBL Australia Node in Single Molecule Science at UNSW to create a collaborative and interdisciplinary environment supportive of conducive to cutting edge molecular biology research.

The award – named in honour of eminent Iranian mathematician and astronomer Khwarizmi – was first established in 1987, and the Foreign Section of the award was introduced in 1991 to recognize outstanding scientific achievements made by researchers from all over the world.
Past recipients include distinguished scientists from Europe, UK, the Americas, Australia and Asia.

Originally published:


Professor Gaus receiving her Khwarizmi International Award