Abstract:
Early diagnosis plays a crucial role in curing the diseases. Especially, nowadays, PCR (Polymerase Chain
Reaction) is used as a Gold Standart for genetically diagnosing illnesses. Alternative ways are being searched
to be used instead of PCR because it takes more time to process, needs more investment, requires fully-armed
laboratory condition which is available and accessible only in developed-countries. An alternative method
which is able to make genetic detection in saliva would have relatively lower infection risks, and patient
comfort would be much higher by the reason of invasive treatment is not processed. e risk of transmission
of contagious infections to medical offi cials or patients is lower with saliva compared to blood samples.
QCM (Quartz Crystal Microbalance) which is a sensing device to be able to detect total mass-change on sensor
surface with 0.5 ng/cm2 sensitivity by the alteration of resonance frequency has been used in this study. Sensor
surface has been exposed to (3-Mercaptopropyl)trimethoxysilane (MPS) coating agent to increase the stability
of sensor and provide a proper surface for suffi cient immobilization. Synthetic Probe DNA (pDNA) has been
placed on the sensor surface to make it be able to detect target DNA (tDNA). After pDNA immobilization
and blocking sensor surface with Bovine Serum Albumin (BSA), the surface has been exposed to negative
control and 3 diff erent concentrations of tDNA at least 3 times for each concentration level. Results show
that genetic material in simulated-saliva has been detected without the need of isolation, puri����� cation and
ampli����� cation at 1.2 ng/cm2 (108 copies/mL) of sensitivity level.