Figure 3.

Visualizing the nature of amplified products from various cycles of PCR. With an increase in cycle number (twenty cycles of an initial round of PCR followed by six, eight or ten cycles of a second round of PCR), there is an evident shift in mobility of PCR products that contain a small RNA insert. Effect of PCR cycle number on three different samples is shown, stressing the importance of titrating the total number of DNA amplification cycles, to avoid saturation of the PCR amplification. Red arrows represent the two sizes of the insert-containing PCR products. PCR products without small RNA inserts migrate as faint bands between 75 and 100 bp (black arrow).