Source: Huang, Z., et al. Application of Biochip Microfluidic Technology to Detect Serum Allergen-specific Immunoglobulin E (sIgE). J. Vis. Exp. (2019)
This video demonstrates a protocol for detecting serum-specific immunoglobulin E using a microfluidic cartridge-based chemiluminescence system. Serum IgEs interact with distinct allergens immobilized in the reaction zone of the cartridge, which are subsequently detected with peroxidase-conjugated anti-IgE antibodies and a chemiluminescent substrate, allowing simultaneous detection of multiple allergen-specific IgEs.
All procedures involving sample collection have been performed in accordance with the institute's IRB guidelines.
1. Basic information of the study group
NOTE: The Allergy Information Repository of the State Key Laboratory of Respiratory Disease (AIR-SKLRD) is a large serum bank established inside the Guangzhou Institute of Respiratory Hospital (GIRH). Initiated in the last decade, the AIR-SKLRD has already started collecting and storing serum samples from patients with allergic diseases and their clinical information (Table 1). The current study was performed with sera from the AIR-SKLRD.
2. Study flow and measurements of interest
NOTE: The microfluidic system needs 100 µL of serum to determine 19 allergens. Venous blood (5 mL) was collected from each patient using a vacuum blood vessel containing separating gel. After centrifuging for 10 min at 1,000 x g, the upper layer was collected for testing. Unused serum was stored at -80 °C. Before testing, the serum was kept at room temperature for 30 minutes and shaken with a vortex mixer. Repeated freeze-and-thaw cycles were avoided.
3. Semi-automation test procedure of the microfluidic system
NOTE: System 2 integrates automatic microfluidic technology, protein microarray, cold light analysis, parallel IgE analysis, and image processing technology. The testing protocol is divided into four parts: preparation of the equipment, sample loading, incubation, and measurement.
Table 1: Patient demographic characteristics. In total, 293 subjects who fulfilled the inclusion criteria were found, with a median age of 23 (interquartile range from 8 to 36 years old). Among them, 170 (58.02%) were male and 123 (41.98%) were female. Also, 92 (31.40%) of them had allergic rhinitis, 117 (39.93%) had allergic asthma, 36 (12.29%) had comorbidity of rhinitis and asthma, and 48 (16.38%) had other allergic diseases, such as a food allergy or skin allergies.
Characteristic | No.(%) |
Gender, n(%) | |
Female | 123(41.98%) |
Male | 170(58.02%) |
Age, year, n(%) | |
Median (25%,75%) | 23(8,36) |
≤10 | 97(33.11%) |
11-20 | 37(12.63%) |
21-40 | 101(34.47%) |
>41 | 58(19.80%) |
Diagnosis, n(%) | |
Allergic rhinitis | 92(31.40%) |
Allergic asthma | 117(39.93%) |
Allergic rhinitis with asthma | 36(12.29%) |
Others | 48(16.38%) |
The authors have nothing to disclose.
Agnitio BioIC Analyzer | Agnitio Science & Technology(Taiwan, China) | BA-G2000 | |
BioIC Allergen specific-IgE Detection Kit | Agnitio Science & Technology(Taiwan, China) | DR17A12 | |
BioIC Cartrideg Placement plate | Agnitio Science & Technology(Taiwan, China) | T20SET | |
BioIC Reagent Dispenser | Agnitio Science & Technology(Taiwan, China) | DS-1 | |
Image two-dimensional barcode machine | Agnitio Science & Technology(Taiwan, China) | NLS-HR200 | |
VORTEX-5 Vortex Mixer | Haimen Kylinbell Lab Lastruments Co., Ltd. | VORTEX-5 |