Methods to monitor the status of a graft prior to transplantation are highly desirable to avoid unnecessary clinical interventions and to optimize the clinical outcome as delayed graft function may lead to costly and lengthy follow-up treatments or even organ loss. As a promising step in this direction we present a method which combines the use of fine needle biopsies, the staining of living cells with dyes suitable to monitor mitochondrial status and cellular integrity and live confocal real time analysis. To confirm the feasibility of such an approach, we obtained fine needle biopsies from rodent kidneys and exposed them to various stress conditions. Following the addition of a range of live stains, biopsy quality was assessed using confocal live cell imaging.

The combination of live cell staining, using fluorescent probes such as TMRM, which respond to changes in mitochondrial membrane potential, with the use of cell viability markers allowed rapid nondestructive serial recording of mitochondrial and cellular parameters in real time. Organ structure was assessed using FITC-labeled wheat germ agglutinin (WGA) which permitted monitoring of cell and tissue morphology. To discriminate between living and dead cells nuclear stains Syto 16 and propidium iodide (PI) were used.

Our data demonstrate that such analyses require minimal time for sample preparation and data acquisition and are well suitable to record organ damage resulting from unphysiological stress prior to transplantation.

Transpl Int. 2014 Biopsychronology: live confocal imaging of biopsies to assess organ function. Ashraf MI, Fries D, Streif W, Aigner F, Hengster P, Troppmair J, Hermann M.

Research Highlight, Nature Reviews Nephrology (2014)

EDITOR´S CHOICE: N.J. White, Lights, Microscope, Action! Science Translational Medicine 6, (2014)

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