Primer-limiting assays for ACTB, CADM1, MAL and hsa-miR-124-2. (A) Amplification curve of MAL in a multiplex qMSP with ACTB. When ACTB-primers are used at a concentration of 400 nM, there is little to no amplification of MAL, which could be due to dNTP depletion by ACTB. (B) The minimum primer concentration of ACTB was 200 nM. (C) When the ACTB-primer concentration was lowered to 200 nM MAL amplification was not hampered. The minimum primer concentration was 200 nM for CADM1 (D), and 400 nM for MAL (E) and miR-124-2 (F).