1970s Topps on the back was in a different typeface. The Burger King set featured 22 cards plus a checklist card. Several cards reflected players changing teams, most notably Pete Rose (Phillies) and Tommy John (Yankees). During the 1970s Topps issued cards featuring the two professional basketball leagues active at the time, the American Basketball Association (ABA) and the National Basketball Association (NBA) until they merged in 1976. Base set 264 cards (NBA/ABA) Size: 2.5 × 3.5 inches Base set 264 cards (NBA/ABA) Size: 2.5 × 3.5 inches Base set 144 cards (NBA) Size: 3⅛ × 5¼ inches. Base set 132 cards
Molecular-weight size marker On the other hand, the size of the DNA pieces are based on the sites where the restriction enzyme cuts. This makes it more difficult to control the size of the fragments in the marker. More recently, another method for constructing DNA molecular-weight size markers is being employed by laboratories. This strategy involves the use of Polymerase Chain Reaction (PCR). This is achieved one or two ways: 1) a DNA target is amplified at the same time via primer sets, or 2) different DNA targets are amplified independently via particular primers. As with experimental samples, the conditions of the gel