A method of characterizing an oil sample includes: flowing a first sample containing an oil through a microfluidic device that has a microfluidic filter while controlling the temperature of the first sample such that it is above wax appearance temperature for the oil and measuring and analyzing pressure difference across the filter over time to detect the presence of fines in the oil. The method further includes: flowing a second sample containing the oil through the microfluidic device while controlling the temperature of the second sample such that the temperature of the second sample is lower than wax appearance temperature for the oil and measuring and analyzing pressure difference across the filter over time as the second sample is filtered to detect the presence of wax in the oil.