elements in biochip 132 and perform analog to digital conversion of the results microprocessor 6 controls and coordinates the operation of the means for applying pressure 2 fluid injection system 3 means for generating a magnetic field 4 and electronic module 5 additionally microprocessor 6 is also used to processes information and test results such as performing the necessary calculation to remove background noise and extract out the user data user interface 7 is connected to microprocessor 6 to receive users 39 instruction and display the test condition and results shown in fig7 is a testing apparatus for magnetoresistive sensor biochips including means for applying pressure 2 which comprises an electronic motor or electronic stepping motor 22 and the control circuit of the electronic stepping motor 21 the output of which are controlled by microprocessor 6 in application solution inlet 181 is sealed first and then driving rod 23 which is the actuation structure of said electrical motor or electrical stepping motor put pressure on pump chamber 151 to inject liquid in reagent reservoir 141 into or through reaction chamber 131 in said cartridge 1 the testing apparatus shown in fig7 further includes 4 the means for generating a magnetic field which comprises electromagnet 41 in series connection with power circuit 42 the operation of power circuit 42 is controlled by microprocessor 6 power circuit 42 provides either a positive or negative current with particular amplitude to the electromagnet accordingly the electromagnet applies either a positive or negative magnetic field on to the integrated cmos magnetoresistive biochip 132 in reaction chamber 131 there can be two directions for the magnetic field applied by electromagnet 41 either parallel or perpendicular to the surface of integrated cmos magnetoresistive biochip 132 in reaction chamber 131 with proper signal processing scheme field in.