In lane 1, EcoRI should have linearised pGT4, and in lane 2, BamHI should have linearised pGT4. The linear DNAs are visible (A), but some oc and ccc leftovers are visible in lane 1 (B). Compare this with the oc and ccc bands in lane 7 (C). So, the EcoRI digestion of pGT4 was partial.

In lane 3, the 3416 bp EcoRI-BamHI fragment is visible (D); the other two small fragments (EcoRI-EcoRV and BamHI-EcoRV) have run off the gel.

Lane 4 shows, that by mistake BamHI must have been used instead of EcoRI for digestion 4. The bands (E) show the pattern of a Lambda BamHI digestion (16841 (F), 7223 (G), 6770 (H), 6527 (I), 5626/5505 (J), which is supposed to be only in lane 5!

In lane 6, this band (K), is more intense than the band above it, because it contains two fragments: the 3758 bp and the 3775 bp fragments, which are too similar in size to be effectively separated in this gel..

It's clear that the smallest expected fragment of the lane 6 digest is not visible.

In lane 8 the very big (uncut) DNA of Lambda (48502 bp) is visible (L).