{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,18]],"date-time":"2026-09-18T04:49:07Z","timestamp":1789706947032,"version":"4.0.1"},"reference-count":27,"publisher":"Wiley","issue":"2","license":[{"start":{"date-parts":[[2002,1,17]],"date-time":"2002-01-17T00:00:00Z","timestamp":1011225600000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Cytometry"],"published-print":{"date-parts":[[2002,2]]},"abstract":"<jats:title>Abstract<\/jats:title><jats:sec><jats:title>Background<\/jats:title><jats:p>Caspase activation is a critical early step in the onset of apoptosis. Cell\u2010permeable fluorogenic caspase substrates have proven valuable in detecting caspase activation by flow cytometry. Nevertheless, detection of early low\u2010level caspase activation has been difficult using conventional area or peak fluorescence analysis by flow cytometry, despite the apparent presence of these cells as observed by microscopy. We describe a method utilizing maximum fluorescence pixel analysis by laser scanning cytometry (LSC) to detect early apoptotic cells.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>The PhiPhiLux\u2010G<jats:sub>1<\/jats:sub>D<jats:sub>2<\/jats:sub> caspase 3\/7 substrate was used in combination with DNA dye exclusion and annexin V binding to identify several stages of apoptosis in EL4 murine thymoma cells by both traditional flow and LSC. LSC analysis of maximum pixel brightness in individual cells demonstrated an intermediate caspase\u2010low subpopulation not detectable by flow or LSC integral analysis. LSC analysis of caspase activity was then carried out using the larger UMR\u2010106 rat osteosarcoma cell line to determine if this apparent early caspase activity could be correlated with localized, punctate caspase activity observed by microscopy.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>The caspase\u2010low subpopulation found in apoptotic EL4 cells was also observable in UMR\u2010106 cells. Relocation to cells with low fluorescence due to caspase activity and subsequent examination by microscopy demonstrated that these latter cells indeed show punctate, highly localized caspase activation foci that might represent an early stage in caspase activation.<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusions<\/jats:title><jats:p>Cells with low\u2010level, localized caspase expression can be detected using maximum pixel analysis by LSC. This methodology allows an early step of apoptotic activation to be resolved for further analysis. Cytometry 47:81\u201388, 2002. \u00a9 2002 Wiley\u2010Liss, Inc.<\/jats:p><\/jats:sec>","DOI":"10.1002\/cyto.10052","type":"journal-article","created":{"date-parts":[[2002,8,25]],"date-time":"2002-08-25T22:13:08Z","timestamp":1030313588000},"page":"81-88","source":"Crossref","is-referenced-by-count":55,"title":["Detection of localized caspase activity in early apoptotic cells by laser scanning cytometry"],"prefix":"10.1002","volume":"47","author":[{"given":"William G.","family":"Telford","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Akira","family":"Komoriya","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Beverly Z.","family":"Packard","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2002,1,17]]},"reference":[{"key":"e_1_2_5_2_2","doi-asserted-by":"publisher","DOI":"10.1016\/0022-1759(94)90373-5"},{"key":"e_1_2_5_3_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0320(19970101)27:1<1::AID-CYTO2>3.0.CO;2-L"},{"key":"e_1_2_5_4_2","doi-asserted-by":"publisher","DOI":"10.1046\/j.1365-2184.1999.00130.x"},{"key":"e_1_2_5_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-1759(00)00233-7"},{"key":"e_1_2_5_6_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1074-7613(00)80428-8"},{"key":"e_1_2_5_7_2","doi-asserted-by":"publisher","DOI":"10.1002\/cyto.990140603"},{"key":"e_1_2_5_8_2","doi-asserted-by":"crossref","first-page":"512","DOI":"10.4049\/jimmunol.157.2.512","article-title":"Sequential acquisition of mitochondrial and plasma membrane alterations during early lymphocyte apoptosis","volume":"157","author":"Castedo M","year":"1996","journal-title":"J Immunol"},{"key":"e_1_2_5_9_2","doi-asserted-by":"publisher","DOI":"10.1126\/science.281.5381.1309"},{"key":"e_1_2_5_10_2","doi-asserted-by":"publisher","DOI":"10.1023\/A:1009649025439"},{"key":"e_1_2_5_11_2","doi-asserted-by":"publisher","DOI":"10.1146\/annurev.biochem.68.1.383"},{"key":"e_1_2_5_12_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0091-679X(01)63026-7"},{"key":"e_1_2_5_13_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0022-1759(99)00054-X"},{"key":"e_1_2_5_14_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0320(20000601)40:2<151::AID-CYTO9>3.0.CO;2-9"},{"key":"e_1_2_5_15_2","doi-asserted-by":"publisher","DOI":"10.1006\/excr.2000.4955"},{"key":"e_1_2_5_16_2","doi-asserted-by":"publisher","DOI":"10.1084\/jem.191.11.1819"},{"key":"e_1_2_5_17_2","doi-asserted-by":"publisher","DOI":"10.1038\/371346a0"},{"key":"e_1_2_5_18_2","doi-asserted-by":"publisher","DOI":"10.1073\/pnas.93.21.11640"},{"key":"e_1_2_5_19_2","doi-asserted-by":"publisher","DOI":"10.4049\/jimmunol.167.9.5061"},{"key":"e_1_2_5_20_2","doi-asserted-by":"publisher","DOI":"10.1038\/sj.cdd.4400536"},{"key":"e_1_2_5_21_2","doi-asserted-by":"publisher","DOI":"10.1083\/jcb.140.6.1485"},{"key":"e_1_2_5_22_2","doi-asserted-by":"publisher","DOI":"10.1159\/000332315"},{"key":"e_1_2_5_23_2","doi-asserted-by":"publisher","DOI":"10.1006\/excr.1999.4477"},{"key":"e_1_2_5_24_2","doi-asserted-by":"publisher","DOI":"10.1002\/1097-0320(20000801)40:4<271::AID-CYTO3>3.0.CO;2-C"},{"key":"e_1_2_5_25_2","doi-asserted-by":"publisher","DOI":"10.1002\/1097-0320(20001001)41:2<83::AID-CYTO1>3.0.CO;2-R"},{"key":"e_1_2_5_26_2","doi-asserted-by":"publisher","DOI":"10.1002\/1097-0320(20010501)44:1<73::AID-CYTO1084>3.0.CO;2-S"},{"key":"e_1_2_5_27_2","doi-asserted-by":"publisher","DOI":"10.1002\/(SICI)1097-0320(19960401)23:4<272::AID-CYTO2>3.0.CO;2-J"},{"key":"e_1_2_5_28_2","doi-asserted-by":"publisher","DOI":"10.1002\/path.1711050103"}],"container-title":["Cytometry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Fcyto.10052","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/cyto.10052","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,10]],"date-time":"2023-10-10T19:41:09Z","timestamp":1696966869000},"score":1,"resource":{"primary":{"URL":"https:\/\/onlinelibrary.wiley.com\/doi\/10.1002\/cyto.10052"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2002,1,17]]},"references-count":27,"journal-issue":{"issue":"2","published-print":{"date-parts":[[2002,2]]}},"alternative-id":["10.1002\/cyto.10052"],"URL":"https:\/\/doi.org\/10.1002\/cyto.10052","archive":["Portico"],"relation":{},"ISSN":["0196-4763","1097-0320"],"issn-type":[{"value":"0196-4763","type":"print"},{"value":"1097-0320","type":"electronic"}],"subject":[],"published":{"date-parts":[[2002,1,17]]}}}