Identifying the TCR gene was like finding a needle in a haystack and Hedrick and Davis designed three-stage process to accomplish this. If I literally had to find a needle in a haystack, first I would burn the haystack down and sieve the ashes for non-combustible objects. Then I would use a magnet retrieve iron or steel objects from the rest of the other metal, stone or ceramics. Finally, I would hand-pick my way through the objects clinging to the magnet. In this analogy, the discarded ash from the burned hay represents ________ and the magnet represents the _____.1 pointRER messages; subtraction hybridization protocolRER messages; use of different T-cell lineages to bind T-cell sequencescytosolic messages; subtraction hybridization protocolcytosolic messages; use of different T-cell lineages to bind T-cell sequencesB-cell messages; subtraction hybridization protocolB-cell messages; use of different T-cell lineages to bind T-cell sequences