Figure 2: The unique and homologous primers used to detect one SNP in the CLRP gene
Left: The cDNA sequences of two CLRP alleles: (A) and (B); two SNPs were found at positions 1592 and 1605. Using the two sequences as templates, the SQPrimer application was used to design the homologous primers (forward primers; yellow) and the primers that are unique to each sequence (reverse primers; red and green). Right: Image of one agarose gel showing one DNA ladder at the left and the PCR products of the amplification of segments of CLRP using DNA as template. For each individual (1 and 2 in the figure) two PCR reactions were carried out: (a) the reaction to recognize the allele A was carried out with its differential primer (green in the sequence) and with the homologous primer at the position 643; (b) the reaction to recognize the allele B was performed with its differential primer (red in the sequence) and with the homologous primer at the position 1293. Thus, the alleles were distinguished by length: the PCR product of allele A was 983 base pairs long while the product of the allele B was 329 long. The individual 1 was homozygous to the allele A of CLRP while the individual 2 was heterozygous.