Karlin firmly believes in the Institute's mission, and he holds himself and his colleagues to a higher standard as a result.[3] This has given him a sense of self-importance as well as a lack of faith in others, and he becomes easily offended by anyone who disturbs his research or fails the tasks he assigns them.[4][5][6] At the same time, this also makes Karlin come off as condescending, though he does not admit this and will only show the slightest approval for those who meet his expectations (or quickly change his tune for those who threaten violence against him).[7][8][9]
Karlin's research is focused on plant science. He spends much of his time managing and monitoring the plant specimens in Hydroponics, and he is proud of it.[10] He is very protective of the specimens and will have no end of complaints for anyone who touches them without his permission; Dean Volkert is one such offender.[11][4] Karlin is also heavily involved in the division's Warwick Homestead Initiative. One of his research areas is the creation of crops which are resistant to the irradiated surface conditions.[12] He has spent years studying this and developing genetically modified seeds which are tested on the surface at Warwick homestead, and because of this, he has a vested interest in the success (and continued secrecy) of the Warwick operation.[13] His long-term exposure to the project has even given him some sympathy for the Warwick family, though BioScience's director, Clayton Holdren, does not share his view.[14]
Another area which Karlin is involved in is the Synth Zoology Initiative. At Director Holdren's behest, Karlin catalogued anomalous incidences of aggression related to the synth gorillas, recommending that they either be destroyed or at the least kept isolated from human personnel for safety reasons.[15] Karlin does not see eye to eye with Director Holdren, believing that Holdren is overly patronizing and contemptuous towards him and is too proud of his own position.[16][17][18]
If Bill Sutton is killed during Building a Better Crop, Karlin will become angry at the Sole Survivor for the rest of the game, claiming that they have ruined months of his life's work.
Conversely, completing Building a Better Crop normally will lead Karlin to occasionally comment on the new crops grown at Warwick homestead.
Karlin will begrudgingly thank the Sole Survivor for their work following completion of Powering Up.
Karlin will express uncertainty regarding the Sole Survivor's directorship after the completion of Mankind - Redefined.
Karlin will comment on the destruction of the Brotherhood of Steel and express condolences for Father's death after the completion of Nuclear Family.
↑The Sole Survivor: "I delivered the seeds." Isaac Karlin: "Good, good. I trust everything went smoothly?" The Sole Survivor: "Does it really matter how smoothly it went?" Isaac Karlin: "Being a member of the Institute means holding yourself to a higher standard. It means efficiency and diligence, attention to detail and an exacting thoroughness. It's not enough just to do a job. It must be done well.At any rate, I'm sure you did the best you could." Note: This is one of the ending dialogue choices for Building a Better Crop. (Isaac Karlin's dialogue)
↑ 4.04.1Isaac Karlin: "One of the ginger plants is gone. Was this another of your medical emergencies?" Dean Volkert: "Doctor Li's been having trouble sleeping, so I used it to make a remedy." Isaac Karlin: "You had no right!" Dean Volkert: "Save it, Isaac. You know I have full access to the garden when it comes to medicinal matters." Note: This is one possible set of randomized lines in the Hydroponics3 dialogue scene. (Isaac Karlin's and Dean Volkert's dialogue)
↑The Sole Survivor: "I delivered the seeds." Isaac Karlin: "Good, good. I trust everything went smoothly?" The Sole Survivor: "Hardly." Isaac Karlin: "Don't tell me the simple act of carrying a packet of seeds from point A to point B proved difficult for you, hm? On second thought, don't answer that. You'll just discourage me. I have little enough faith in people as it is. I'd prefer not to lose any more." Note: This is one of the ending dialogue choices for Building a Better Crop. (Isaac Karlin's dialogue)
↑The Sole Survivor: "Look, sometimes things don't go the way you planned. That's life." Isaac Karlin: "Is that supposed to excuse your behavior?How disappointing. I hoped you would at least have the sense to take responsibility for your actions.Your carelessness has jeopardized months of research.The entire project will have to be suspended indefinitely, at best.In the meantime, I suggest that you think very carefully about whether you truly belong here." Note: This is one of the ending dialogue choices for Building a Better Crop if Bill Sutton was killed. (Isaac Karlin's dialogue)
↑Isaac Karlin: "Yes, yes, I'm sure that whatever you have to say is very interesting, but now simply isn't a good time." The Sole Survivor: "Someone's a little full of himself." Isaac Karlin: "Hardly. There is no place for ego in science. I am simply trying to tell you, in as polite as manner as possible, that I am busy. Now, goodbye." (Isaac Karlin's dialogue)
↑The Sole Survivor: "Those mental equations will get a lot tougher after I sock you in the jaw." Isaac Karlin: "Er, what? Now just a moment. There's no need to get angry. If an apology will suffice to stem your anger, then I'll offer it. So nice talking to you. Goodbye!" (Isaac Karlin's dialogue)
↑The Sole Survivor: "Don't patronize me, pencilneck." Isaac Karlin: "I... I meant no offense. Just, uh... well, let's move on." Note: This is a partial dialogue response for the conversation at the start of Building a Better Crop. (Isaac Karlin's dialogue)
↑Isaac Karlin: "Most men lack the patience to observe and document plant growth." (Isaac Karlin's dialogue)
↑Isaac Karlin: "Please resist any urge you might feel to eat the specimens in the hydroponic garden." (Isaac Karlin's dialogue)
↑Institute scientist: "Doctor Karlin, a retrieval team just sent back preliminary test results from one of our surface crops." Isaac Karlin: "Go on." "The specimens are showing an abnormal growth rate. They were designed to thrive in a radiated environment, but we didn't expect these results." Isaac Karlin: "What a peculiar result...I'd like it brought back to the lab so I can test the rate of cellular degeneration." Institute scientist: "I'll let them know immediately." (Institute scientist's and Isaac Karlin's dialogue)
↑Isaac Karlin: "Good day, director.I need your assistance with a simple errand on the surface. Allow me to explain.Some time ago, we covertly replaced the family patriarch at Warwick Homestead with a synth.He's been field-testing a variety of genetically-modified seeds that I created. Take this packet of seeds to the Roger Warwick synth. Be careful with these! They represent years of genetic manipulation and enhancement.Hopefully you can manage such a simple task." Note: This is Karlin's conversation at the start of Building a Better Crop if the player has completed Nuclear Family. (Isaac Karlin's dialogue)
↑Isaac Karlin: "Have you had time to examine my latest reports on batch two-seven-four?" Clayton Holdren: "Not yet. I've been reviewing Father's plans to expand our operations at Warwick. He's eager to get that going, so I've had to put everything else to one side." Isaac Karlin: "I wonder how the Warwick family is doing. Young Wally must be close to ten years old by now. It's remarkable that any child can survive for so long up there." Clayton Holdren: "I... try not to think too much about it. We have more than enough to occupy ourselves here. Those people are the last remnants of a dying past. It's best not to dwell on the subject." Isaac Karlin: "They're still people, and they're suffering. We can at least admit that it's regrettable. After all, how can we hope to redefine mankind if we can't even hold on to our own humanity?" Clayton Holdren: "Well, that's a question best left to our colleagues in the Robotics division." Isaac Karlin: "Yes, well... I suppose you're right." (Isaac Karlin's and Clayton Holdren's dialogue)
↑Isaac Karlin: "*Sigh* How unsurprising. No doubt Doctor Holdren preferred to boast about the importance of the BioScience division rather than tell you the details of my situation.The man is useless, I tell you. Very well, I suppose it falls to me." (Isaac Karlin's dialogue)
↑Isaac Karlin: "Frankly, I resent Doctor Holdren claiming that I 'need help'. There's a subtle insinuation there that I don't care for. I simply require your services to make a delivery to one of our operatives on the surface." (Isaac Karlin's dialogue)
↑Clayton Holdren: "Isaac, have you had a chance to run the alkalinity test on last week's soil sample from Warwick?" Isaac Karlin: "I told you that I would. Well, unsurprisingly, I have." Clayton Holdren: "We'd be lost without you, Isaac." Isaac Karlin: "Thanking a man for doing his duty is like thanking a dog for barking." Note: This is one possible randomized set of lines in the Hydroponics4 dialogue scene. (Clayton Holdren's and Isaac Karlin's dialogue)
