TIRF imaging of α4-CFP/β1-YFP integrins (expressed in GD25). Movie shows expression only at the spreading cell surface on VCAM-1.

Courtesy of Young-min Hyun, University of Rochester Medical Center, USA

Time-lapse sequence depicting long-term behavioral migration GFP expressing stem cells.

Song, Y, Bahnson A, et. al. Leukemia. 2010 January ; 24(1): 153-161. doi:10.1038/leu.2009.191. Movie reproduced by permission of the Journal of Leukemia

To view more videos by Song Y. et. al., see the following:

Time Lapse Video of MEG-like Cell Enlargement.

These time lapse video sequences of MEG-like cells were assembled from sorted HPC, ST-HSC, and LT-HSC subsets of transgenic GFP+ bone marrow cells at various time points after seeding onto irradiated bone marrow stromal cells.. The interval between each image represents 10 scans, or 100 minutes total elapsed time. The video display rate is 15 frames/sec, or approximately one day per second. A footer was added to the images indicating: 1) the tracked cell name or founder cell family name, 2) the viewfield location name, 3) the scan number, and 4) the elapsed time from the start of imaging (left to right).

Presumed megakaryocyte differentiation is demonstrated by pronounced cellular enlargement followed by disintegration. In most cases, one or more divisions occurred prior to MEG-like cell enlargement, with the division and differentiation processes occurring simultaneously among sisters or cousins. Only the enlargement and disintegration images are shown.

MEG-like cell enlargement occurred earlier for the HPC founder subset than for the LT-HSC and ST-HSC subsets. There was frequent involvement of CA formation and expansion from CA-founder cells within the same viewfields as the MEG-founder cells. This made tracking of late appearing pre-differentiated MEG-like cells particularly difficult for the LT-HSC and ST-HSC subsets. As shown by this video, the occurrence of MEG-like cells is readily identifiable during the enlargement process.

Time-lapse sequence of composite fluorescent green images from 324 individual view-fields acquired at 100 minutes intervals over a total elapsed time of almost 7 weeks.

The layout was formed from patterns of 108 viewfields in each of three wells, connecting adjacent sides as appropriate. The grid below indicates the edges of individual images bounded by 3 rectangles with 6 x 6 = 36 images in each rectangle, each rectangle offset halfway to the right from top to bottom within the circle representing one well of a 24well plate.

Clockwise from the upper left quadrant are: 1) LT-HSC, 2) ST-HSC, 3) HPC subtypes and 4) LT-HSC raw green fluorescent images without correction for autofluorescence or normalization for lamp intensity fluctuations.

The image sequence illustrates the process of expansion of hematopoietic cell colonies on stroma.