Fig. 6. Polymerase chain reaction (PCR) analysis of Aedes aegypti cDNA (A-CA)-like sequences in cDNA-amplified RNA samples taken from regions of the midgut of larval Aedes aegypti. PCR was performed using exact primers for the cloned A-CA. Equal quantities of total RNA were amplified and analyzed from anterior midgut (lane 2), gastric caeca (lane 3), posterior midgut (lane 4), whole gut (lane 5), Malpighian tubules (lane 6) and a water template control (lane 7). Note the primary product in caeca and posterior midgut samples at the expected size of approximately 894 nucleotides. Also note the absence of this band from other gut regions but the appearance of bands of higher molecular masses. Lane 1 is a 100 base pair (bp) molecular mass ladder.