A slide holder comprising a rectangular frame having two side walls facing each other, a first end wall facing a second end wall, the second end wall having a latch pivotally attached thereto, the latch capable of being pivoted in such a manner as to enable locking and unlocking of the slide holder in a slide holder carrier. The slide holder carrier has a first end wall, a first side wall, a second end wall, a second side wall, and a shaft running from the first end wall of the slide holder carrier to the second end wall of the slide holder carrier. At least one slide holder is rotatably mounted on the shaft.