Lysosomes are membrane-bound cell organelles found in most animal cells. Lysosomes maintain acidic environment of about pH 4.5, and contain acid hydrolase enzymes that break down waste materials and cellular debris. GeneCopoeia offers LysoBeacon™ probes that appear to accumulate in acidic organelles. Our LysoBeacon™ probes exhibit a pH-dependent increase in fluorescence intensity upon acidification.