A system is disclosed. The system includes at least one image acquisition device configured to obtain one or more images of sample containers in a sample container holder. It also includes an image analysis device coupled to the at least one image acquisition device. The image analysis device is configured to analyze, by a processor, the one or more images of the sample containers in the sample container holder, to determine (a) a presence or absence of sample containers at sample container holder locations in the sample container holder, and (b) sample container characteristics of the sample containers in the sample container holder, wherein the sample container characteristics include one or more of cap color, cap shape, labels and markers associated with the sample containers, or one or more sample container holder characteristics.