An ambidextrously operated charging handle for use with the M16 family of firearms is provided. Oligonucleotides are provided which amplify MTB DNA and which are useful in carrying out real time PCR of DNA obtained from formalin-fixed and paraffin-embedded tissue samples. The FFT engine utilizes a minimal number of multipliers to perform the twiddle multiplications in an efficient pipeline. A second dielectric layer is provided on the surface of the water-containing first dielectric layer.