May 1, 2020.
Protein and DNA microarray are technologies that prepare probe molecules or captured molecules that will bind with its molecular partner, such as the antibody of the bacteria or the complimentary DNA. The technique is a candidate for the screening test where many species or strains can be measured at the same time with the advancement of spot fabrication, one can print a substance on a surface [1]. (Figure 1)
Fabrication of protein microarray, DNA microarray, or pattern of protein is the spot morphology where a spot morphology has an influence on fluorescence light intensity [2]. Understanding and controlling these processes are crucial for microarray production (Figure 2).
Fig. 1 (a) shows the preparation of the protein microarray of alpha-fetoprotein (AFP) and (b) the polymer spot on the substrate.
Fig. 2 Effect of the "coffee ring" on the polymer spot of microarray.
Wettability and surface tension are important factors on the spot formation. In this study, the self-assemble monolayer and / or polymer brush and / or polymer hydrogel which is 3D is shown in Figure 1 (a). Each substance has its own unique conditions for the preparation of different substances.
The objective of this research is to develop alpha-fetoprotein (AFP) for a screening of liver cancer [3] and/or down syndrome detection [4]. An important indicator of the diagnosis is the level of AFP presence in the patient's serum. AFP is a tumor marker, which is an important indicator of malignant necrosis that can cause liver cancer [5-7]. Currently, screening can be done by measuring the amount of AFP in the serum and in combination with the ultrasound results. Level of AFP found in normal people is less than 20 ng/ml. If the AFP content is greater than 100 ng/ml, there are high chances of developing liver cancer [8].
From previous research [1], studying the protein array of AFP system, both anti-AFP immobilization condition, proper surface preparation and AFP quantitative measurement, found that AFP content can be detected with detection limit 0.01 ng/ml (with 100 times dilution of the sample) as shown in Figures 1 and 3.
Fig. 3 shows the results of the amount of AFP at concentrations from 0-10 ng/ml.
This project is the collaboration of Mahidol University, Srinakharinwirot University, King Mongkut's Institute of Technology Ladkrabang, King Mongkut's Institute of Technology North Bangkok and the Immunology and Clinical Microscopy, Ramathibodi Hospital.
References
Reported by
Asst. Prof. Dr. Toemsak Srikhirin
Department of Physics and Capability Building Unit in Nanoscience and Nanotechnology, Faculty of Science, Mahidol University, Bangkok - 10400, Thailand
E-mail: toemsak.sri@mahidol.ac.th