The apparatus comprises an elongate base having means on one end for mounting the base on a laboratory ring stand and {TAIL ~ means} on {HEAD ~ the other end} of the base for allowing a technician to hold the microcentrifuge tube in one hand and to open and close the cap without requiring a second hand 
The apparatus comprises an elongate base having means on one end for mounting the base on a laboratory ring stand and { TAIL ~ means } on { HEAD ~ the other end } of the base for allowing a technician to hold the microcentrifuge tube in one hand and to open and close the cap without requiring a second hand
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