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Frequency Locked Microtoroid Optical Resonators as a Non-Invasive Tumor Biopsy Alternative

Su, Judith and Goldberg, Alex and Raubitschek, Andrew and Stoltz, Brian M. and Fraser, Scott E. (2013) Frequency Locked Microtoroid Optical Resonators as a Non-Invasive Tumor Biopsy Alternative. Biophysical Journal, 104 (2). 528A. ISSN 0006-3495. doi:10.1016/j.bpj.2012.11.2924.

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Whispering gallery mode optical resonators offer an unusual coupling of rapid response time and ultra-sensitive biological and chemical detection. We have improved the signal to noise ratio of microtoroid optical resonators ∼1000-fold over standard techniques by using laser frequency locking and have applied this to assay tumor progression in mice by sensing the low concentrations of exosomes, shed by tumor cells, in serum samples collected from the animals. Serum samples from normal or experimental mice cause no shift in the resonance wavelength of the microtoroids; however, after using antibodies toward specific tumor markers to sensitize the toroid surface, we detected changes in the resonance frequency of the microtoroid when exposed to the serum of tumor-implanted mice. Serum from control (tumor-free) mice caused no shift. The wavelength shifts observed were 600 times the noise and drift of the sensor, even for a million fold dilution of the serum sample. Analysis of the shifts showed unitary steps of ∼ 0.5 fm, suggesting that the assay may be sensitive enough to detect individual binding events, offering a means to analyze the size of the biomolecules that are binding to the resonator. If validated, this approach offers a non-invasive tumor “biopsy,” exploiting the circulation of blood to collect a sample of tumor surfaces without the need to find or access the tumors.

Item Type:Article
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Stoltz, Brian M.0000-0001-9837-1528
Fraser, Scott E.0000-0002-5377-0223
Additional Information:© 2013 Biophysical Society. Published by Elsevier Inc.
Issue or Number:2
Record Number:CaltechAUTHORS:20130501-082658216
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Official Citation:Judith Su, Alex Goldberg, Andrew Raubitschek, Brian Stoltz, Scott E. Fraser, Frequency Locked Microtoroid Optical Resonators as a Non-Invasive Tumor Biopsy Alternative, Biophysical Journal, Volume 104, Issue 2, Supplement 1, 29 January 2013, Page 528a, ISSN 0006-3495, 10.1016/j.bpj.2012.11.2924. (
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:38195
Deposited By: Ruth Sustaita
Deposited On:01 May 2013 15:38
Last Modified:09 Nov 2021 23:35

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