Single‐Cell Analysis in a Plastic Microfluidic Channel with a Hadamard Transform Microscopic Fluorescence Image System

Abstract

In this report, a single‐channel chip fabricated with polymethylmethacrylate (PMMA) material was applied to sampling single pollen cells stained with acridine orange (AO). A home‐made Hadamard transform (HT) microscopic fluorescence image system was used to detect the fluorescence signal emitted from the cells and obtain 511 × 512‐pixel two‐dimensional image of single cells, by which single‐cell fluorescence was measured accurately and the DNA content was determined quantitatively. The single‐cell sampling and the on‐line imaging were discussed in detail. The PMMA chip, with a suitable channel approximately 100 µm in depth and 108 µm in width, was proved suitable for single‐cell sampling. The HT instrument was well matched to the on‐line imaging due to the powerful resolving ability. The reliability of the measurement was evaluated by measuring the fluorescent intensity of AO‐stained pollens in the channel for 11 times, with a coefficient of variation (CV) of 2.78%. The method was used for quantitative measurements of DNA contents in two kinds of pollens with satisfactory results, which show that the method is rapid, accurate, and reliable in single‐cell analysis.

Keywords:

• Hadamard transform
• Microchip
• Single‐cell analysis
• Fluorescence image
• Microscopic imaging

Acknowledgment

The authors acknowledge the National Natural Science Foundation of China for financial support of this work (project no. 20075019).