Interferometric fringe patterns interrogate entire cell surfaces in fluorescence photobleaching recovery measurements of lateral diffusion

B. George Barisas; Heidi M. Munnelly; Deborah A. Roess

doi:10.1117/12.273559

7 May 1997 Interferometric fringe patterns interrogate entire cell surfaces in fluorescence photobleaching recovery measurements of lateral diffusion

B. George Barisas, Heidi M. Munnelly, Deborah A. Roess

Author Affiliations +

Proceedings Volume 2980, Advances in Fluorescence Sensing Technology III; (1997) https://doi.org/10.1117/12.273559
Event: BiOS '97, Part of Photonics West, 1997, San Jose, CA, United States

Abstract

Lateral diffusion of cell surface proteins is commonly measured by spot fluorescence photobleaching recovery (FPR) methods where the 1/e² radius of the interrogated spot is typically 0.5 micrometers . On an 8 micrometers lymphocyte the effective spot area represents only 1/500 of the total surface. An FPR lateral diffusion measurement of a protein expressed as 50,000 copies per cell thus reflects the dynamics of only 100 molecules and this greatly limits the precision and reproducibility of FPR measurements. A new method for interferometric fringe pattern FPR permits simultaneous interrogation of the entire surface of round cells. Fringe patterns are generated interferometrically within the optical path of a conventional microscope FPR system so that spot photobleaching measurements can be performed interchangeably. Methods for interpreting recovery kinetics on round cells and for determining the fraction of mobile protein are presented. Fringe FPR data of the murine MHC Class II antigen I-A^k (wt) expressed on M12.C3.F6 cells showed fluorescence signals improved 100-fold relative to spot FPR, with corresponding improvements in S/N ratios of recovery traces. Diffusion coefficients of 2.07 +/- 0.37 and 1.79 +/- 0.97 X 10^-10 cm²sec^-1 were obtained by fringe and spot methods, respectively. The corresponding mobile fractions of I-A^k were 66.1 +/- 7.8% and 63.4 +/- 18.0%. Improved reproducibility of fringe over spot results are slightly less than signal improvements predict. There may thus be substantial variation from cell to cell in proteins dynamics and this method may permit the assessment of such variation.

Citation Download Citation

B. George Barisas, Heidi M. Munnelly, and Deborah A. Roess "Interferometric fringe patterns interrogate entire cell surfaces in fluorescence photobleaching recovery measurements of lateral diffusion", Proc. SPIE 2980, Advances in Fluorescence Sensing Technology III, (7 May 1997); https://doi.org/10.1117/12.273559

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available