Reliably measuring DNA input quality and quantity. (A) Relative DNA yield in terms of ACTB copy numbers per micron of biopsy tissue, stratified by age and sample quantity groups. Outliers, i.e. data points exceeding 1.5 times the respective interquartile distances, are not represented. (B) Relative amount of detectable samples, in terms of possessing a minimum of ACTB copies, as a function of the total amount of ACTB. Gray horizontal lines represent possible, minimal cutoffs to assure sufficient DNA quantity and quality, set here at 50 and 100 ACTB copies.