Algae counter is a key tool in the fields of water ecological monitoring, environmental assessment, and aquaculture, and its operational standardization directly affects the accuracy and reliability of data. The following provides a detailed explanation of the four core steps of sample preparation, instrument debugging, observation and counting, and result processing.

1、 Sample collection and preprocessing: laying the foundation for data

The sample should be representative, and when collecting, it should avoid floating objects on the water surface and sediment at the bottom. The vertical stratified sampling method (such as surface, middle, and bottom layers) should be used to mix evenly. If quantitative analysis is required, the sampling volume (such as 1L) needs to be recorded synchronously. For water samples containing a large amount of suspended particles, they need to be pre filtered through a 30-50 μ m pore size filter membrane to remove large impurities, but attention should be paid to avoiding excessive filtration and loss of target algae. If it is necessary to distinguish between live and dead algae, neutral red staining solution with a final concentration of 0.1% can be added, and live cells will be stained red. The sample should not be stored for more than 24 hours. Low temperature (4 ℃) and light avoidance storage can slow down the morphological changes of algae.

2、 Instrument debugging: Accurately matching observation conditions

Preheat the machine for 10-15 minutes to ensure stable light source. Select a suitable counting pool (such as a phytoplankton counting box) based on algal density, and dilute high abundance samples to a cell count of ≤ 100 per field of view. Adjust the objective magnification (usually 10 x or 40 x) and use the coarse/fine focus knob to make the cell image clear and focused. Set appropriate light intensity - some algae (such as blue-green algae) are sensitive to strong light and need to reduce the brightness of the light source to prevent morphological changes caused by light damage; Diatoms and other groups with decorative structures require strong transmission of light to highlight their shell surface characteristics. If the instrument is equipped with automatic scanning function, it is necessary to calibrate the scanning speed and image resolution in advance to avoid missed or repeated counting.

3、 Observation and Counting: Standardized Operation to Avoid Deviation

Use a zigzag path to traverse the entire counting room to avoid missing edge areas. Overlapping cells need to be separated into a single layer by adjusting the focal length and counted. If they cannot be distinguished, they should be counted as half individuals. For linear populations (such as Microcystis) or gelatinous populations (such as Tremella), it is necessary to count and record the population size as a whole. When encountering species that are difficult to identify, microscopic photographs can be taken for comparison. It is recommended to count at least 2 parallel samples per sample and take the average to reduce random errors. If the coefficient of variation of a single count is greater than 15%, the number of repetitions should be increased to 5 or more.

4、 Result Calculation and Quality Control

Calculate the raw data according to the formula "cell density=count value x dilution factor/sampling volume". Special attention should be paid to unit conversion (such as cells/L). Establish a quality control system: ① Blank control (sterile water) for detecting reagent contamination; ② Accuracy of the verification method for spiked recycling experiments; ③ Regularly calibrate the counting field of view with a standard particle solution. The data records should include environmental parameters such as sampling time, location, water temperature, pH, etc., to facilitate subsequent correlation analysis.

5、 Maintenance and upkeep: Extend equipment lifespan

After each use, promptly clean the residue of the counting tank, rinse it with distilled water first, and then soak it in 75% ethanol for disinfection. Objective lenses can only be wiped unidirectionally with a small amount of alcohol mixture dipped in lens cleaning paper. When not in use for a long time, the power cord should be removed, covered with a dust cover, and stored in a dry environment. Regularly check the lifespan of the light source bulb and replace it in a timely manner to ensure stable light intensity. Electronic components should avoid contact with corrosive liquids, and professional personnel should be contacted for repair in case of malfunction.