Number of bacteria (using of DAPI for identifying and counting) in Toolik Lake water column and other lakes sample throught the summer from 1992-2000. There is no data for 2006.
Data set ID:
EML revision ID:
For years 1992 -1994
2 ml of gluteraldehyde-preserved lake water was stained with 200 ul 100ug/ml
4'6 diamidino-2-phenylindole (DAPI), final concentration 10 ug/ml, in a 15 ml
Millipore filtration apparatus. After 5 minutes, the sample was vacuum filtered
through a 0.22 um pore size black Nuclepore 25mm filter. The filter was mounted
on a microscope slide using Cargille B immersion oil. Ten fields were counted
using a Zeiss epifluoresencce microscope.
Cell count= (x/field)(2.04 x 10^4 field/ml) = #/ml
For years 1995-2000
After transport to the laboratory at Woods Hole, MA, 2 ml of glutaraldehyde-preserved lake water from each depth was mixed with 2 ml 0.2 um filtered phosphate buffered saline to reduce humic interference and 0.1% Triton X-100 or Nonidet P-40 to improve cell permeability and stored overnight at 4*C. The sample was stained with 200 ul 100ug/ml 4'6 diamidino-2-phenylindole (DAPI), final concentration 10 ug/ml. After 5 minutes, the sample was vacuum filtered through a 0.22 um pore size black Nuclepore 25mm filter in a 15 ml Millipore filtration apparatus. The filter was mounted on a microscope slide using Cargille A immersion oil. Ten fields were counted using a Zeiss epifluoresencce microscope. Reference Citations: Hobbie, J.E., T.L. Corliss and B.J. Peterson, Seasonal patterns of bacterial abundance in anArctic lake. 1983. Arctic and Alpine Research 15:252-259.Porter, K.G. and Y.S.Feig The use of DAPI for identifying and counting aquatic microflora.1980. Limnology and Oceanography 25:943-948
Version 1: Combined all the years from 92hobact to 2000hobact files. JimL 29May13
Version 2: added all the researchers from 1992-2000; and all the sites. JimL 9Jun13
Version 3: Checked keywords against the LTER network preferred list and replaced non-preferred terms. Jim L 15Jan14
Version 4: Changed Distribution URL since the LTER network DAS system is being discontinued. JimL 9Apr2015
Version 5: Camp Pond coordinates were wrong. It is a pond near the southern end of the old Toolik airstrip. Nov 2019 Jim L
Download a comma delimited (csv) or Excel file (includes metadata and data sheets).
Use of the data requires acceptance of the data use policy --> Arctic LTER Data Use Policy
To cite this data set see the citation example on the LTER Network Data Portal page for this data set.