The performance of each IGRA is assessed through the use of an internal control which measures the IFN-γ response against phytohaemagglutinin (PHA).
This current study design however is potentially more robust given the placebo arm, which acts as an internal control, quantitative measures of MPH response by two raters, namely parents and teachers, as well as consideration of comorbid disorders.
Internal quality control measures are used for assays.
Internal quality control measures (Burkina Faso, Rwanda and Senegal) included using control wells (positive and negative) provided with manufacturer's screening kit on each test plate.
In addition, the laboratory performed internal quality control measures when introducing the enzymatic method, in order to ascertain that results were comparable.
Internal quality control was conducted using standard laboratory protocol and procedures, including having slides randomly read by different laboratory technicians or the chief technician/supervisor for internal quality control measures.
This includes establishing internal quality control measures and external validation systems that are linked into regional and national and if possible international external quality monitoring schemes, although implementing a quality assurance system for laboratories in developing countries is expensive and logistically complicated.
In the second experiment only the expression levels of TNF-α, IL-1β, IL-6 and IL-8, and the internal control, were measured.
In a previous study, we showed that GAPDH protein signal is a good indicator as an internal control to measure the protein quality from each tissue sample [ 33].
One of the obligations of outside accountants is to assess a client's internal controls, including measures to prevent and detect misconduct by employees.
Lead concentrations in unprocessed muscle tissue collected from the shank and well away from the bullet path of the same 13 deer were all below the detection limit of 2.0 µg/g and served as internal controls for measures of lead in ground meat.
