Purified king crab trypsin differs in size from purified sardine trypsin. 250 ng of purified king crab and sardine trypsin were run on a SDS-PAGE gel and stained with silver staining for detection. The result shows that purified king crab trypsin (lane 7 and 8) is a slightly bigger molecule residing in the 28 – 30 kDa area compared to the purified sardine trypsin (lane 3 and 4) at 24 – 25 kDa. Additional purified fish trypsins tested (anchovy (lane 5 and 6), yellow tail, jacopever, spotted mackerel (not shown)) displayed similar size as purified sardine trypsin. Lane 1, 2 and 10 contain protein standards, respectively 10 μl SeeBlue®,10 μl Mark 12™, 16 μl SeeBlue®. Lane 9 is empty.