Detection of viability of micro-algae cells by optofluidic hologram pattern

Abstract

A rapid detection of micro-algae activity is critical for analysis of ship ballast water. A new method for detecting micro-algae activity based on lens-free optofluidic holographic imaging is presented in this paper. A compact lens-free optofluidic holographic imaging device was developed. This device is mainly composed of a light source, a small through-hole, a light propagation module, a microfluidic chip, and an image acquisition and processing module. The excited light from the light source passes through a small hole to reach the surface of the micro-algae cells in the microfluidic chip, and a holographic image is formed by the diffraction light of surface of micro-algae cells. The relation between the characteristics in the hologram pattern and the activity of micro-algae cells was investigated by using this device. The characteristics of the hologram pattern were extracted to represent the activity of micro-algae cells. To demonstrate the accuracy of the presented method and device, four species of micro-algae cells were employed as the test samples and the comparison experiments between the alive and dead cells of four species of micro-algae were conducted. The results show that the developed method and device can determine live/dead microalgae cells accurately.

Development of lens-free holographic microscopes using multiheight and multispectral phase recovery methods

“…Researchers have explored the fingerprint shadow patterns of microalgae species to observe flocculation,(83) morphological changes (84), and to judge the liveness and death of cells. (85) Under the LHM system, microalgae samples can be imaged on the solution and do not present significant movements in the time scale of the performed image recordings.…”