optical members or more preferably such as microprobe 301 shown in fig8 that has been fabricated to have a tip size less than 20 microns to enter at the stratum corneum and rest in or proximal of extracellular space of the stratum basale of the epidermis microprobe 301 includes a distal tip portion 303 extending proximally 9 8914 mm to a base portion 305 both base portion 305 and tip portion 303 are tapered with a substantial step where the tip portion meets the base portion base portion 305 has a width of 5 1068 mm at its proximal end and a length of 9 5791 mm and tapers at approximately four degrees to the step where it meets the tip portion 303 it is preferred that the optical member be molded to the final shape preferably using a two part rtv rubber silicone mold using known molding techniques that mold is prepared using a hard durometer type silicone such as that sold under the trade designation g 380 by silicones inc such a silicone is suitable for small parts the first part of the mold is prepared by creating a pattern from a modified micropipette tip and a pulled silica optical fiber tip 307 specifically the micropipette tip is an eppendorf style tip that has been trimmed at the bottom to expand the diameter to approximately 600 microns the pulled silica optical fiber tip.