Problem:
The polymerase chain reaction (PCR) amplifies a nucleotide sequence between two PCR primers. You want to generate a knock-in of a marker at a specific locus on the genome using homologous recombination. You designed a knock-in vector with 5' and 3' homology arms of 50 bp each with a 350 bp knock-in sequence in between. In the targeted genomic region, there is a distance of 100 bp between the two homologous regions. To identify the cell that contains the correct DNA fragment knocked in, you designed a PCR reaction with primers flanking the homologous regions, which generated a 1000-bp product in intact cells. Please calculate the expected size of the PCR product from the region with a successful knock-in. Give your answer in base pairs, and round to the nearest whole number. Just enter the number, nothing else. Need Assignment Help?