100 attached to a tubular knock out pin drive motor 104 meshes with the tubular knock out pin elongate indexing gear 96 tubular knock out pin elongate indexing gear 96 is movably mounted within knock out pin driver chamber 32 on a tubular knock out pin sliding support 108 a tubular knock out pin linear driver 112 is connected to the tubular knock out pin sliding support 108 a vacuum connection 116 is located at a proximal end of tubular knock out pin 92 a control unit 118 fig2 controls the operation of drive motors 56 80 104 linear drivers 64 88 112 and a vacuum source connected to port 116 the control unit 118 may be programmed by the user to collect a set of specimens from discreet locations and is capable of outputting a record of such locations to correlate individual samples to the discreet locations a cross sectional view of the sample cassette housing 36 and the tissue sample cassette 40 is shown in fig5 a tissue sample cassette 40 includes tissue containment chambers 120a 120b 120c and 120d the hollow outer piercing needle 44 cannular inner cutter 68 and tubular knock out pin 92 are shown positioned in tissue containment chamber 120a sample cassette 40 includes indexing ridges 124 which cooperate.