Quality Control & Assurance Flashcards

Why is quality control important in flow cytometry?

Answer: Ensures accurate results

Quality control (QC) is paramount in flow cytometry to ensure the reliability, reproducibility, and accuracy of experimental results. Regular QC checks, including instrument calibration and daily performance monitoring, help identify and correct potential issues with the instrument or reagents. This rigorous approach minimizes variability and ensures that the data collected is trustworthy and scientifically sound, leading to confident conclusions.

What is a control sample used for?

Answer: Change dye colors

Control samples are indispensable in flow cytometry experiments because they serve as a reference point for interpreting experimental data. They help to identify background fluorescence, assess non-specific binding, determine positive and negative populations, and ensure proper compensation. By comparing experimental samples to appropriate controls, researchers can confidently draw conclusions about their specific markers and cell populations, ensuring data validity.

How often should cytometers be calibrated?

Answer: Daily or before use

Flow cytometers should be calibrated and their performance verified daily or before each use. This routine quality control involves running standardized fluorescent beads to check instrument settings, laser alignment, fluidics, and detector sensitivity. Daily calibration ensures consistent and reproducible data acquisition over time, which is crucial for reliable experimental results and accurate comparisons between different runs and experiments.

Which beads are used to verify instrument performance?

Answer: Fluorescent calibration beads

Fluorescent calibration beads, also known as reference or QC beads, are specifically used to verify and standardize the performance of flow cytometers. These beads have known and consistent fluorescence intensities and sizes, allowing researchers to check instrument sensitivity, linearity, and alignment. Running these beads daily helps ensure that the instrument is operating optimally and that data collected is comparable across different experiments and days.

Why must reagents be stored correctly?

Answer: Ensure performance and shelf life

Reagents are chemical substances essential for accurate experimental results in fields like cytometry. Incorrect storage conditions, such as exposure to inappropriate temperatures or light, can degrade their chemical integrity and stability. Proper storage ensures that reagents maintain their intended performance characteristics and remain effective for their specified shelf life, which is crucial for reliable and reproducible scientific work.

What is intra-laboratory quality control?

Answer: Control within the same lab

Intra-laboratory quality control refers to the systematic procedures and practices implemented *within a single laboratory* to monitor and ensure the consistent quality and reliability of its own test results. This internal monitoring involves regular checks on instruments, reagents, and methods. Its purpose is to guarantee that the lab's operations consistently meet established standards and produce accurate data.

How can data reproducibility be improved?

Answer: Following SOPs and logs

Data reproducibility means that an experiment, when repeated under the same conditions, yields consistent results. Following Standard Operating Procedures (SOPs) ensures that every step of a process is performed identically each time, minimizing variability. Detailed logs document all experimental parameters, changes, and observations, allowing for accurate replication and troubleshooting, thereby significantly enhancing the reliability and trustworthiness of scientific data.

What should be reviewed during an audit?

Answer: Maintenance logs and QC charts

During an audit, the primary goal is to verify that a laboratory's operations adhere to established quality standards and regulatory requirements. Maintenance logs provide documented evidence that equipment is regularly serviced, calibrated, and functioning correctly. Quality Control (QC) charts visually demonstrate that tests are consistently performed within acceptable limits, proving the reliability and accuracy of the lab's analytical processes.

What is an inter-laboratory comparison?

Answer: Testing same samples in different labs

An inter-laboratory comparison, also known as external quality assessment or proficiency testing, involves multiple laboratories analyzing identical samples and comparing their results. This process helps evaluate the accuracy, precision, and comparability of results across different institutions. It identifies potential biases or discrepancies between labs, ensuring overall data quality and harmonization in diagnostic or research settings.