Monthly Archives: June 2016

Rapidly labeling antibodies with luminescence

Labelled cells10 June 2016:

CNBP and Macquarie University researchers have successfully developed a novel indirect universal detection reagent that rapidly labels antibodies with luminescence within seconds and without the need for any complicated bioconjugation procedures. The reagent, reported in the journal ‘Scientific Reports’, can be used to directly label antibodies for several time-gated luminescence applications, e.g., bioimaging, cell labeling and detection, and flow cytometry.

The work was co-authored by CNBP researchers Dr Andrew Care and Dr Nima Sayyadi and led by CNBP Associate Investigator Dr Anwar Sunna.

Pictured (top left) – giardia cyst cells labeled with europium chelate.

Publication title: A Novel Universal Detection Agent for Time-Gated Luminescence Bioimaging

Authors: Nima Sayyadi and Andrew Care ( first co-authors), Russell E. Connally, Andrew C. Try, Peter L. Bergquist and Anwar Sunna

Abstract:
Luminescent lanthanide chelates have been used to label antibodies in time-gated luminescence (TGL) bioimaging. However, it is a challenging task to label directly an antibody with lanthanide-binding ligands and achieve control of the target ligand/protein ratios whilst ensuring that affinity and avidity of the antibody remain uncompromised. We report the development of a new indirect detection reagent to label antibodies with detectable luminescence that circumvents this problem by labelling available lysine residues in the linker portion of the recombinant fusion protein Linker-Protein G (LPG). Succinimide-activated lanthanide chelating ligands were attached to lysine residues in LPG and Protein G (without Linker) and the resulting Luminescence-Activating (LA-) conjugates were compared for total incorporation and conjugation efficiency. A higher and more efficient incorporation of ligands at three different molar ratios was observed for LPG and this effect was attributed to the presence of eight readily available lysine residues in the linker region of LPG. These Luminescence-Activating (LA-) complexes were subsequently shown to impart luminescence (upon formation of europium(III) complexes) to cell-specific antibodies within seconds and without the need for any complicated bioconjugation procedures. The potential of this technology was demonstrated by direct labelling of Giardia cysts and Cryptosporidium oocysts in TGL bioimaging.

The paper is available online.

Director speaks at pain conference in Sicily

Mark Hutchinson Low Res Edit 01646 June 2016:

Professor Mark Hutchinson (Director, CNBP) attended the Pain Mechanisms and Therapeutics Conference in Taormina, Sicily, from 5-10th June 2016.

While there he gave an invited talk, speaking on the topic, “The impact of innate immune signaling on sex differences in exaggerated pain states and analgesic requirements; integration of clinical and experimental human and preclinical data.”

Conference information is available online.

 

Ultrasensitive imaging of unique nanoruby probes

Wan Razali6 June 2016:

Our CNBP researchers describe a wide-field time-gated photoluminescence microscopy system, customised for ultrasensitive imaging of unique nanoruby probes in this latest paper published in the Journal of Biophotonics.

Publication Title: Wide-Field Time-Gated Photoluminescence Microscopy for Fast Ultrahigh-Sensitivity Imaging of Photoluminescent Probes.

Authors: Wan A W Razali (pictured top left), Varun K A Sreenivasan, Carlo Bradac, Mark Connor, Ewa M Goldys and Andrei V Zvyagin.

Abstract: Fluorescence microscopy is a fundamental technique for the life sciences, where biocompatible and photostable photoluminescence probes in combination with fast and sensitive imaging systems are continually transforming this field. A wide-field time-gated photoluminescence microscopy system customised for ultrasensitive imaging of unique nanoruby probes with long photoluminescence lifetime is described. The detection sensitivity derived from the long photoluminescence lifetime of the nanoruby makes it possible to discriminate signals from un-wanted autofluorescence background and laser backscatter by employing a time-gated image acquisition mode. This mode enabled several-fold improvement of the photoluminescence imaging contrast of discrete nanoru-
bies dispersed on a coverslip. It enabled recovery of the photoluminescence signal emanating from discrete na-norubies when covered by a layer of an organic fluorescent dye, which were otherwise invisible without the use of spectral filtering approaches. Time-gated imaging also facilitated high sensitivity detection of nanorubies in a biological environment of cultured cells. Finally, we monitor the binding kinetics of nanorubies to a functionalised substrate, which exemplified a real-time assay in biological fluids. 3D-pseudo colour images of nanorubies immersed in a highly fluorescent dye solution. Nanoruby photolumines-cence is subdued by that of the dye in continuous  excitation/imaging (left), however it can be recovered by time-gated imaging (right). At the bottom is schematic diagram of nanoruby assay in a biological fluid.

The paper is available online.

 

CNBP researcher at Gordon Research Conference

Jingxian Yu_low_sq5 June 2016:

CNBP Researcher, Dr Jingxian Yu, from the University of Adelaide, presented recent research on “Peptide-Based Quantum Interferometers and Their Sensing Applications” at the prestigious Gordon Research Conference on Electronic Processes in Organic Materials in Lucca, Italy, from 5-10 June 2016.

At the conference, chemists, physicists and materials scientists from all over the world addressed the key challenges in the field related to photophysical and charge transport processes in organic materials and discussed how molecular architectures could provide new and enhanced functionalities.

New team members at University of Adelaide

cnbplogosquare12 June 2016:

We welcome several new team members to the CNBP and the University of Adelaide team more generally.

The first is Mr Bryden Quirk, joining us from Perth and who works alongside Chair of BioPhotonics Professor Rob McLaughlin. Bryden is working on the “fibre optical needle imaging” project and sits in the School of Medicine, CNBP and in the Biological Sensing and Medical Diagnostic Theme at the Institute for Photonics and Advanced Sensing (IPAS).

Next up is Dr Jiawen Li, Lecturer, also joining us from Perth, who works with Bryden Quirk and Professor Rob McLaughlin on the project “optical coherence tomography (OCT)” and sits in the School of Medicine, CNBP and in the Biological Sensing and Medical Diagnostic Theme at IPAS.

Welcome! It’s great to have you both on board!

 

CNBP researcher visits China and Israel

Jingxian Yu_low_sq1 June 2016:

CNBP researcher from the University of Adelaide, Dr Jingxian Yu, was invited by several academic facilities in both China and Israel to disseminate his recent research. Lectures were given to the Department of Chemical Engineering at Xiamen University, China, Professor David Cahen’s group at the Weizmann Institute of Science, and the Department of Materials Engineering at Ben Gurion University of the Negev, Israel.

Whilst in China, Jingxian initialised the collaboration on electron transport in single molecules with Professor Wenjing Hong. He also met Professors Deying Wu, Shoufa Han, Dongping Zhan, and Jiawei Yan.

In Israel, he met Professors David Cahen, Mudi Sheves, Ron Naaman, and Drs Ayelet Vilan, Cunlan Guo, Sabyasachi Mukhopadhyay at the Weizmann Institute of Science, Professors Nurit Ashkenasy, Gonen Ashkenasy, Raz Jelinek, Hanna Rapaport and Drs Ronit Bitton, Mark Schvartzman, Hadar Ben Yoav, and Yifat Miller at the Ben Gurion University of the Negev. Networking provided a number of possible future collaborations.

Itinerary: Lectures:
June 1, 2016: School of Chemical Engineering, Xiamen University, China
June 13, 2016: Professor David Cahen Group, Weizmann Institute of Science, Israel.
June 14, 2016: Department of Materials Engineering at Ben Gurion University of the Negev, Israel

Jingxian Yu_China visit