I would add however that your question specifically asked about quality not quantity. In that regard the Agilent Bioanalyser system has most commontly replaced agarose gels
In contrast the fluorimeter measures the quantity of your cDNA and has thus replaced the spectrophotometer and is an laternative to the Nanodrop
Dear Shivendra, though it is a multifactorial issue, as to achieve the best quality cDNA, your RNA quality crucially matters along with the RNA input standardization for reverse transcription phase.
But, in short, cDNA quality can be checked and affirmed easily by observing the expression pattern of your HKG and for that select the one best, which is not affected at all under your experimental conditions. This approach is quite useful, especially when your lab does not have expensive equipment like Agilent Analyzers or Agilent Tape Stations.
Run your cDNA of all samples both, undiluted (original) and diluted (lets say 1:10 & 1:25) with your selected HKG and compare their Ct values.
If, in your undiluted cDNA sample, the HKG Ct behavior lies within the desired range you are expecting, so just use that cDNA for further experiments. Otherwise, if it is not the case, then look for the cDNA dilution which best suites for your experiment and dilute your cDNA accordingly.
Ct value above 25 for a HKG, represents compromised cDNA quality. Hence, your cDNA is no more having a good quality.
Whereas, just running your cDNA on a gel cannot assess the cDNA quality, rather you may get smeared or striated bands, which may arise confusions in your mind to use or not to use it.
Fluorometric approaches (Qubit) only for quantitation and don,t forget that good quantity does not necessarily corresponds to good quality, which I have personally experienced several times.