Introduction

Quality Control (QC) is a process whereby a combination of control samples and statistical analysis is used to assess the accuracy and reliability of assay results received from the laboratory.

Reference materials (also known as standards) are used to assess the accuracy of a result by comparing the assay result received from the laboratory to the known (certified) value of the standard.

A blank standard refers to a sample of barren material for which the known value is essentially zero. This type of standard is used to check for contamination rather than accuracy.

OCRIS makes use of a Shewhart chart and a blanks chart to test these two types of control samples. See later for a more detailed discussion of these charts.