I have created the following plot using the script:

merged_data.plot(x = "Ratio_IP1_Average_1", y = "Ratio_IP1_Average_2", kind = "scatter", color = "#830051") plt.text(44.8, 45.6, "+ DMSO", horizontalalignment='left', size='medium', color='#68D2DF', weight='semibold')

enter image description here

I now want to add horizontal and vertical lines which show the variance around my control value, so any outliers can be highlighted. These values are within the data frame, but I am required to call a specific cell, ideally using the column name. How would I do this?