Determination of refractive index for single living cell using integrated biochip

Abstract

This paper reports a novel method for measuring the effective refractive index (RI) of single living celI with a small integrated chip. This microchip is able to determine the RI of living cell in real time without extra requirements of fluorescence labeling and chemical treatments, offering low cost and high accuracy meanwhile. 11 might provide an efficient approach for diseases or cancer diagnosis. The measurement system integrates laser diode, microlenses, and microfluidic channels onto a mopolithic chip. In the experiments, two standard polystyrene beads with .nominal IUS are: employed to calibrate the system and five types of cancerous cells are subsequently measured. The results indicate that the RI of the tested cells ranges from 1.392 to 1.401, which is larger than typical value 1.35-1.37 for normal cells.

Integral refractive index determination of living suspension cells by multifocus digital holographic phase contrast microscopy

“…Knowledge of the integral cellular refractive index allows the determination of the cell thickness and for adherently grown cells, the cell shape from the obtained phase contrast images. 3,7 Previously published methods for the determination of the refractive index of single cells require a preparation of the sample, 7 an exchange of the cell culture medium, 8 or specific microfluidic equipment, 9,10 which may affect the sample, is time consuming, or often not applicable. Here, a method for the determination of the cellular refractive index by digital holographic microscopy is described that requires only cells in suspension and a calibrated image scale.…”

Determination of the integral refractive index of cells in suspension by digital holographic phase contrast microscopy

“…The determination of the cell thickness and the shape of adherently grown cells requires precise information about the integral cellular refractive index [3,7]. Previously published methods for the determination of the refractive index of single cells demand a preparation of the sample [7], an exchange of the cell culture medium [8] or specific micro fluidic equipment [9,10] which may affect the sample, is time consuming, or often not applicable. A digital holographic microscopy based method for the determination of the integral cellular refractive index is described.…”

Healthy Aging

“…The refractive index measured in the serum of Wistar rats shows a time-dependence being measured an increase of 1,34136 from birth to 1.35175 (250g) to adulthood [94]. The effective refractive index of a single cell [101] is determined by the refractive index of cellular constituents, and its determination provides us data on the size and volume of the cell, nucleus volume, setting of certain dysfunction at the cellular level [97,99,100].…”