Semi-automatic enzyme-linked immunosorbent assay analyzerIt is a detection device based on the principle of enzyme-linked immunosorbent assay (ELISA), mainly used for qualitative and quantitative analysis of analytes in biological samples. The basic working principle is to form an antigen antibody complex by specifically binding enzyme labeled antibodies to antigens in the test sample. Subsequently, specific substrates are added to react with enzymes, producing color changes or fluorescent signals. These signals are directly proportional to the concentration of the analyte, so they can be quantitatively analyzed through photoelectric colorimetry or fluorescence detection methods to achieve qualitative and quantitative detection of specific components in the sample.
Semi-automatic enzyme-linked immunosorbent assay analyzerIt mainly consists of the following five modules:
1、 Optical detection system: the core of accurately capturing signals
light source module
Function: Provide stable light sources (such as halogen lamps, LEDs) that cover the wavelength range required for detection (usually 400-750nm).
Features: Some high-end models use multi wavelength light sources, supporting simultaneous detection of multiple fluorescent or chemiluminescence signals.
Case: When detecting tumor markers, it is necessary to read the color change of enzymatic reaction products at a wavelength of 450nm, and the stability of the light source directly affects the accuracy of the results.
Spectral system
Filter/Grating: Select specific wavelengths (such as 450nm, 630nm) through a filter, or use grating splitting to achieve multi wavelength scanning.
Optical path design: Adopting a single beam or dual beam structure, the dual beam can reduce the impact of light source fluctuations on detection (such as synchronous measurement of reference channel and sample channel).
Photoelectric detector
Type: Commonly used photodiode (PD) or photomultiplier tube (PMT), which converts optical signals into electrical signals.
Sensitivity: PMT has higher sensitivity than PD and is suitable for detecting low concentration samples (such as early cancer biomarker screening).
2、 Mechanical transmission system: achieving precise positioning of samples
Sample carrier board
Structure: Standard 96 well microplate (8 rows x 12 columns), some models support 48 well or 384 well plates to accommodate different detection scales.
Material: Polypropylene (PP) or Polystyrene (PS), with good optical transparency and chemical stability.
Carrier board moving mechanism
Drive method: Stepper motor or servo motor drive, which achieves precise movement of the carrier board in the X/Y axis direction through screw or belt transmission.
Positioning accuracy: usually up to ± 0.1mm, ensuring that the detection hole is aligned with the optical path.
Case: When detecting HIV antibodies, it is necessary to sequentially read the absorbance values of each sample in a 96 well plate, and the movement error of the plate should be controlled within 0.05mm.
Incubation module (optional)
Function: Some models integrate temperature control incubation function, which maintains the reaction temperature (such as 37 ℃) through heating plates or semiconductor refrigeration chips.
Uniformity: The temperature fluctuation range is usually ≤± 0.5 ℃ to avoid local overheating affecting enzyme activity.
3、 Control and Data Processing System: The Core of Intelligent Operations
Main control unit
Hardware: Embedded processors based on ARM or x86 architecture, running real-time operating systems (RTOS) or Windows CE.
Function: Coordinate the operation of various modules (such as light source control, board movement, data acquisition), support multitasking parallel processing.
user interface
Display: LCD or touch screen, displaying detection parameters (such as wavelength, temperature), real-time curves, and results.
Operation: Set the detection program (such as wavelength scanning, standard curve fitting) through button or touch input.
Data processing software
Algorithm: Supports quantitative analysis methods such as standard curve method, four point method, endpoint method, etc., automatically calculates sample concentration or activity.
Storage: Built in memory or external USB flash drive, can store detection data (such as absorbance values, concentration values) and experimental logs.
Output: Supports printing reports or exporting to PC software (such as Excel, SPSS) for further analysis.
4、 Auxiliary function module: Improve operational convenience
Sample addition auxiliary device
Type: Manual pipette or electric pipette workstation (requires external connection), some models integrate a sample gun mounting bracket to reduce human error.
Case: When detecting cytokines, it is necessary to accurately add 50 μ L of reagent, and the sample gun holder can ensure a sample volume deviation of ≤± 2%.
Waste liquid treatment system
Structure: The waste liquid tank or vacuum pump is connected to the waste liquid bottle to automatically collect cleaning solution or reaction waste liquid, avoiding cross contamination.
Safety design: The waste liquid bottle is equipped with a liquid level sensor, which automatically alarms and prompts for replacement when the liquid is full.
Cleaning module (optional)
Function: Clean the microplate by spraying or soaking to reduce the interference of residual reagents on subsequent testing.
Efficiency: The single cleaning time is usually ≤ 2 minutes, supporting continuous detection of multiple batches of samples.
5、 Shell and safety design: ensuring stable operation of equipment
Shell material
Material: Aluminum alloy or engineering plastic, with good heat dissipation and anti-interference ability.
Protection level: usually up to IP20, preventing dust from entering the internal circuit.
safety protection
Overload protection: The motor automatically stops when overloaded to avoid mechanical damage.
Leakage protection: Equipped with a built-in leakage circuit breaker to ensure safe operation.
Heat dissipation design: The fan or heat sink forces heat dissipation to maintain an internal temperature of ≤ 40 ℃.