Sam Holtzen, PhD
@samholtzen.bsky.social
husband had a piano recital today :)
December 8, 2025 at 4:25 AM
husband had a piano recital today :)
i remember seeing this chart in high school as a fun lesson"both sides are extreme, trust the center" and looking back now i grow weary
September 5, 2025 at 2:28 PM
i remember seeing this chart in high school as a fun lesson"both sides are extreme, trust the center" and looking back now i grow weary
this is the job openings page for ICE
August 20, 2025 at 3:50 AM
this is the job openings page for ICE
they really don't make pharmaceutical ads like this anymore
July 25, 2025 at 3:44 PM
they really don't make pharmaceutical ads like this anymore
happy pride month from her
June 3, 2025 at 3:20 AM
happy pride month from her
I spent hours on this application. Unbelievable. 🧪
May 16, 2025 at 2:34 PM
I spent hours on this application. Unbelievable. 🧪
So honored to have received the Divisional Postdoctoral Fellowship award from BBE here at Caltech!!
May 12, 2025 at 5:08 PM
So honored to have received the Divisional Postdoctoral Fellowship award from BBE here at Caltech!!
got engaged and it's two boys
March 18, 2025 at 2:48 AM
got engaged and it's two boys
S-phase stalling and proliferation are two different outcomes, so we wanted to test the fates of ZD cells after division. We found that zinc must be present during late S-phase and at the S/G2 transition for cells to cycle after division. This quiescence is accompanied by expression of p21.
March 12, 2025 at 7:22 PM
S-phase stalling and proliferation are two different outcomes, so we wanted to test the fates of ZD cells after division. We found that zinc must be present during late S-phase and at the S/G2 transition for cells to cycle after division. This quiescence is accompanied by expression of p21.
This inhibition is accompanied by increases in replication stress markers, but importantly NOT markers of double-stranded breaks (shown in SI). These markers are reversible upon resupply of zinc.
March 12, 2025 at 7:22 PM
This inhibition is accompanied by increases in replication stress markers, but importantly NOT markers of double-stranded breaks (shown in SI). These markers are reversible upon resupply of zinc.
Since DNA synthesis occurs in S-phase, we wondered if DNA synthesis is inhibited in response to ZD. We found that DNA synthesis is inhibited in as little as two hours of ZD, and that this inhibition is reversible upon resupply of zinc.
March 12, 2025 at 7:22 PM
Since DNA synthesis occurs in S-phase, we wondered if DNA synthesis is inhibited in response to ZD. We found that DNA synthesis is inhibited in as little as two hours of ZD, and that this inhibition is reversible upon resupply of zinc.
To answer this, my team of undergrads and I set out to conduct pulse/chase experiments to determine what phase (if any) is sensitive to zinc deficiency. We found that cells require zinc at the G1/S transition and in S-phase to complete S-phase on time.
March 12, 2025 at 7:22 PM
To answer this, my team of undergrads and I set out to conduct pulse/chase experiments to determine what phase (if any) is sensitive to zinc deficiency. We found that cells require zinc at the G1/S transition and in S-phase to complete S-phase on time.
reading a book about strategic thinking and this is one of the examples.
maybe this book isn't aligned to my values after all
maybe this book isn't aligned to my values after all
March 6, 2025 at 5:00 PM
reading a book about strategic thinking and this is one of the examples.
maybe this book isn't aligned to my values after all
maybe this book isn't aligned to my values after all
this is the clarity of purpose and economy of language democrats should be aiming for
February 20, 2025 at 2:57 PM
this is the clarity of purpose and economy of language democrats should be aiming for
haha it's two boys. happy valentine's day to my wonderful partner 💕
February 15, 2025 at 12:36 AM
haha it's two boys. happy valentine's day to my wonderful partner 💕
probably the coolest book i've found at a used bookstore ever
January 13, 2025 at 4:46 AM
probably the coolest book i've found at a used bookstore ever
when you do object oriented programming, this is the object
January 2, 2025 at 5:00 AM
when you do object oriented programming, this is the object
Catsitting these two boys for the week 💕 the nephews
January 1, 2025 at 7:23 PM
Catsitting these two boys for the week 💕 the nephews
you KNOW if a hotel has a mirror like this, i'm taking pictures in it
December 29, 2024 at 3:41 AM
you KNOW if a hotel has a mirror like this, i'm taking pictures in it
Thinking about the time @amypalmerzinc.bsky.social and I got to see a tube of ORIGINAL GFP from Shimomura at Woods Hole and it STILL fluoresces after 30+ years. What a cool piece of history :)
December 28, 2024 at 4:31 PM
Thinking about the time @amypalmerzinc.bsky.social and I got to see a tube of ORIGINAL GFP from Shimomura at Woods Hole and it STILL fluoresces after 30+ years. What a cool piece of history :)