What is the difference between Inter-assay and intra-assay?

Intra-assay CV is a measure of the variance between data points within an assay, meaning sample replicates ran within the same plate. Inter-assay CV is a measure of the variance between runs of sample replicates on different plates that can be used to assess plate-to-plate consistency.

How do you calculate inter and intra-assay CV?

The % CV for each sample is calculated by finding the standard deviation of results 1 and 2, dividing that by the duplicate mean, and multiplying by 100. The average of the individual CVs is reported as the intra-assay CV.

How is ULOQ calculated?

ULOQ should be calculated based on expected Cmax + RSD% of this value. So if your Cmax is 100 ng/ml and variability for Cmax is 35% then your “safe” ULOQ should be 140-150 ng/ml.

What is assay validation?

Assay validation is performed for the analysis of drugs, metabolites, and biomarkers to ensure that the test results are precise and accurate, and the generated data is reasonably robust in supporting drug development and other intended purposes.

What is intra assay precision?

Intra-assay precision, known as repeatability, describes how similar results are when always obtained by the same operator or the same measuring system in the same lab. It involves trusting the run today and as well as tomorrow.

What is CV percent?

Percent Coefficient of Variation Plot Point The %CV plot point is the subgroup sample standard deviation divided by the subgroup mean, multiplied by 100. In effect, %CV is the percentage of the mean represented by the standard deviation – a relative measure of variation.

How do you measure Lloq and ULOQ?

Determine the LLOQ by identifying the lowest mean level above which the %CV < 20% for the greater majority of the samples. Determine the ULOQ by identifying the highest mean level below which the %CV < 20% for the greater majority of the samples.

What is the limit of LOD and LOQ?

Limit of Blank (LoB), Limit of Detection (LoD), and Limit of Quantitation (LoQ) are terms used to describe the smallest concentration of a measurand that can be reliably measured by an analytical procedure.

Why is assay validation important?

Assays must be precise, robust, and specific during use in preclinical studies and clinical trials in order to assure that drug candidates can be accurately evaluated for safety and efficacy. Validation plans assure that an assay will work reliably, even if an assay is run at different sites or by different users.

How do you create an assay method?

Assay development can be broken into three steps: system design, parameter design, and tolerance design. System design involves ensuring that the right chemistry, right materials, right technology, and right equipment are being used.