Clinical Microarray System Developed for Genetic Analysis Screening

In precision medicine, preoperative or postoperative genetic testing can be used to stratify patients according to disease states and select appropriate drugs, enabling efficient delivery of personalized treatment.

Postoperative monitoring can also be used to predict the possibility of recurrence and other prognostic factors. With the advancement of liquid biopsy genetic testing, preventive medicine is expected to have an impact in the future in terms of estimating the risk of morbidity and preventing diseases.

Clinical Scientists at the Yamaguchi University Graduate School of Medicine (Ube, Japan) and their colleagues at Toyo Kohan Co., Ltd (Shinagawa, Tokyo, Japan) developed a novel microarray-based genetic analysis system that uses a Peltier element to overcome the issues of conventional microarrays, such as the long measurement time and high cost. They constructed a microarray system to detect the UDP-glucuronosyltransferase gene polymorphisms UGT1A1*6 and UGT1A1*28 in patients eligible for irinotecan hydrochloride treatment for use in clinical laboratories. Irinotecan hydrochloride is used to treat cancer.

Threshold values were set based on the mean and standard deviation of genotype determination values for each genotype calculated from 22 human specimens. Then, genotype determination values were calculated using the developed genetic analyzer for 111 human specimens that had already been examined using the existing Invader UGT1A1 Molecular Assay (Sekisui Medical, Tokyo, Japan), and the genotypes were determined based on the genotype determination thresholds that were set. Amplification was performed on a Mastercycler Pro S PCR system (Eppendorf, Hamburg, Germany).

The investigators reported that the hybridization temperature reached its target in 1/27th of the time required by the conventional system. They assessed 111 human clinical samples and found that their results agreed with those obtained using existing methods. The total time for the newly developed device was reduced by 85 minutes compared to that for existing methods, as the automated DNA microarray eliminates the time that existing methods spend on manual operation.

The authors concluded that a microarray system suitable for clinical use was developed using a surface treatment that enables high-density and strong DNA fixation. Using the assay system for the UGT1A1*28 and UGT1A1*6 polymorphisms, the optimal hybridization temperature and thresholds for genotype determination were set. In a performance evaluation using 111 samples, the results of the present device were comparable to those of an existing assay. Therefore, they proposed that the system developed in their study is suitable for genetic testing in clinical laboratories. The study was published on December 26, 2022 in the journal Practical Laboratory Medicine.

Related Links:
Yamaguchi University Graduate School of Medicine
Toyo Kohan Co., Ltd
Sekisui Medical 
Eppendorf