Internal control: This is a control sequence that is amplified in the same reaction as the target sequence and detected with a different probe (i.e., duplex PCR is carried out). An internal control is often used to rule out failure of amplification in cases where the target sequence is not detected.
How it works. A symporter is an integral membrane protein that is involved in the transport of many differing types of molecules across the cell membrane. The symporter works in the plasma membrane and molecules are transported across the cell membrane at the same time, and is, therefore, a type of cotransporter. The transporter is called a symporter, because the molecules will travel in the same direction in relation to each other. This is in contrast to the antiport transporter. Typically, the ion will move
If a molecule is accompanied by another molecule so that both molecules at the same time, together are transported into or out of the cell through a protein channel, then the condition is called symport. If a molecule enters the cell, at the same time another molecule will move out of the cell. This exchange of molecules through a protein is called antiport. Uniport transports one solute at a time across the membrane. Symport transports the solute and a co-transported solute at the same time in the same direction in or out of the cell.