def extract_muMax(df_Annotations):
    """
    Extracts the growth rate (Slope) for each sample.

    Parameters
    ----------
    df_Annotations : pandas.DataFrame
        The dataframe contains the results of a linear fit through the
        exponential growth phase.

    Returns
    -------
    df_mu : pandas.DataFrame
        A dataframe that shows the calculated maximal growth rate for each
        sample.
    """
    # Delete index name and transform
    df_Annotations.index.name = None
    df_mu = df_Annotations.T
    # Keep only sample name and slope
    df_mu.reset_index(inplace=True)
    df_mu = df_mu.rename(columns={"index": "samplename_OD"})
    df_mu = df_mu[["samplename_OD", "Slope"]]
    df_mu["samplename_OD"] = df_mu["samplename_OD"].str[:6]
    # Rename slope
    df_mu.rename(columns={"Slope": "mu[/h]"}, inplace=True)
    return df_mu