Indicate whether you would use a fluorescent organic molecule (O), in situ hybridization (H), or a coupled fluorescent protein (P) to visualize the cells and their molecules in each of the following cases. Your answer would be a five-letter string composed of letters O, H, and P only, e.g. OHOOO.
( ) You would like to see where in the early Drosophila embryo the mRNA encoding a certain transcription regulator is located.
( ) You would like to see the nuclei and count them in an early mouse embryo.
( ) You would like to visualize chromosome 3 in a human cell culture derived from a patient's tissue, based on specific sequences present on this chromosome.
( ) You would like to observe the oscillations in Ca²? ions inside a fertilized frog egg.
( ) You would like to compare the localization of two transcription regulatory proteins in cultured human T cells.