# 28-Jul-2021 Analyse-it v5.90: Support for the updated CLSI EP6-Ed2 protocol and inverse predictions

Recently we’ve been busy updating Analyse-it to stay aligned with the latest updates to the CLSI protocols, and added a new inverse prediction feature.

If you have you can download and install the update now, see or visit the . If maintenance on your license has expired you can renew it to get this update and forthcoming updates, see .

**New CLSI EP6-Ed2**

The CLSI recently released guideline , which replaces the EP06-A published in 2003.

EP06-A relied on fitting a linear (straight line), 2^{nd} (parabolic) and 3^{rd} (sigmoidal) order polynomials to the data. A method was then determined to be linear or possibly non-linear based on statistical criteria. The degree of nonlinearity was then calculated as the difference between the linear fit and the best fitting non-linear model (parabolic or sigmoidal curves). Nonlinearity could then be compared against allowable nonlinearity criteria.

The new CLSI EP6-Ed2 protocol no longer requires fitting polynomial models to determine linearity. Instead, the deviation from linearity is calculated as the difference between the mean of each level and a linear fit through the data. That can then be compared against the allowable nonlinearity criteria. Other changes to the protocol include experimental design and there is now more focus on the structure of the variance across the measuring interval.