Several microscopy techniques are available today that can detect a specific protein within the cell. live cell analysis of fission yeast can be found, for example on how to make a movie of the meiotic chromosomal behaviour 4. In this particular experiment we focus on subnuclear organisation and how it is affected during gene induction. We have labelled a gene cluster, named Chr1, by the introduction of binding sites in the vicinity of the genes. The gene cluster is usually enriched for genes that are induced early during nitrogen starvation of fission buy 21462-39-5 yeast 5. In the strain the nuclear membrane (NM) is usually buy 21462-39-5 labelled by the attachment of mCherry to the NM protein Cut11 giving rise to a reddish fluorescent transmission. The Spindle Pole body (SPB) compound Sid4 is usually fused to Red Fluorescent Protein (Sid4-mRFP) 6. In vegetatively growing yeast cells the centromeres are usually attached to the SPB that is embedded in the NM 7. The SPB is usually identified as a large round structure in the NM. By imaging before and 20 moments after depletion of the nitrogen source we can determine the distance between the gene cluster (GFP) and the NM/SPB. The mean or median distances before and after nitrogen depletion are compared and we can thus quantify whether or not there is a shift in subcellular localisation of the gene cluster after nitrogen depletion. cells. 3. Microscopy buy 21462-39-5 Initialise the fluorescence microscopy by turning around the mercury/xenon lamp, the microscope and the computer. Place the yeast growth chamber in the fluorescence microscope. Make use of a 63 X objective or a 100 X objective with NA=1.3 or higher. If an oil objective is used, add oil. Use the bright field to find the cells and get a sharp picture. The settings for the fluorescence microscopy vary depending on the fluorochromes used to label the yeast cells and the microscope. We make use of a confocal microscope Zeiss LSM 700 Laser Scanning Microscope with Plan-Apochromat 63x oil objective lens (NA=1.4) with the 16-collection average plane scan setting. The pinhole should be set to 1-1.1 Airy models, which gives an optical slice of 0.8 mm. We detect GFP in Track 1 using the filter set for Alexa 488 with a beam splitter at 582 nm, thus detecting wavelengths between 488 and 582 nm. In Track 2 we make use of a filter set optimal for mCherry using a beam splitter at 578 nm, thus detecting wavelengths between 578 and 600 nm. This means that in Track 2 both the mRFP (SPB) and NM (mCherry) will be detected. Take as many pictures needed to be able to measure in 60 different cells for each strain. Usually 15 pictures of impartial microscopy fields are enough. It is recommended that a new growth chamber with new cells is made if your microscopy time exceeds 60 moments. 4. Quantitative measurement of subcellular distances Open the pictures HSP27 in the Zeiss Zen Light Edition program. Using the measurements tool measure the distance in m between the different fluorochromes in all the cells where all the signals are in the same focal plane. Adjust the light intensity and contrast to identify the centre of the fluorescent transmission. This simplified protocol uses only two different colours and hence the SPB and NM are in the same channel. The SPB is usually singled out by its large.