(at around 53 mins) The "receiver" in Blade's left ear is not there after the punch to the face but is there after the silver spike was embedded in his shoulder by Quinn.
(at around 1h 50 mins) In the final fight between Blade and Frost, the bloodstain on Frost switches from the left side of his face to the right, then back to the left.
(at around 27 mins) When Blade is being injected with serum in the hideout he spots Karen trying to escape. Whistler lets go of Blade's hand to pursue Karen, but then a close up on Blade has Whistler still holding it.
(at around 1h 40 mins) When Blade collapses nearly unconscious out of the blood collection chamber, his hands are at his sides. When he hits the floor, they are above his head and help support his fall.
(at around 13 mins) When Quinn bites Dr. Jenson, the doctor's wig slips to the side and we see a glimpse of her real hair. In the next shot, her wig is back in place.
(at around 55 mins) During the subway tunnel fight, the subway train takes over 60 seconds to pass by Blade and Quinn. If the train is traveling at 30 mph, then the train would have to be a half-mile long, or 66 train cars at 40 feet per car. A standard subway train is 8 or 10 cars long.
(at around 1h 19 mins) Silver has a melting point of 962 degrees C. Some alloys melt a little lower, but in any case, these kinds of temperatures are not obtained using a small, open-top, thin-walled bench top melting pot. Blade uses regular equipment for normal lead projectiles (melting point 327.5 degrees C), which would not work with silver.
(at around 39 mins) There is a shot (speeded up) of the Moon rising. However as it rises it moves from right to left when it should be the other way round. Without using a computerized telescope to line up a camera to point exactly where the Moon will rise, the film-makers filmed the Moon setting and then reversed the footage. What they should have was to also flip the scene.
(at around 1h 40 mins) The vampires, especially the Pure Bloods speak Romanian, probably because their ancestors come from Transylvania, yet in the temple when one of the guards holds the female Pure Blood still for the ceremony she says "Skloni te ruke s mene" which means "Take your hands off me", but in Serbian, not Romanian.
Following the fight with the vampires in the hospital the police open fire on Blade despite his clearly carrying a member of the medical staff at the hospital. There is no way police officers would open fire so indiscriminately at a perp carrying a hostage.
(at around 1h 35 mins) There are twelve pure-bloods needed to complete the ritual, but Mercury seemingly kills one of them before the ritual starts. However, careful viewing of their entry to the temple floor shows there to be thirteen pure-bloods in the group. Evidently they brought a spare.
EDTA (ethylenediaminetetracetate), the anticoagulant Blade
uses in the glass darts, is not blue. The powdered form is white and produces a clear, colorless solution. However it is possible they would have coloured it blue in order to make it distinguishable from other liquids such as Blade's serum to avoid any mix-ups.
The vampires do not seem concerned at any time about the damage caused to their original Bible, despite its importance historically and to their immediate plans. That's because it's the information and not the artifact that's important, and the information has all been stored on Frost's computer.
(at around 1 min) When Blade is born at the beginning of the movie, the doctors talk about a Caesarean section to get the child out. When his mother reaches out for her newborn child, her belly is still very round and there is no blood.
(at around 8 mins) In the background of the vampire nightclub after Blade's small killing spree a man is visible in the background, covered in head to toe with blood, however his bright blue shorts don't have a speck on them, even though it rained from the roof a few moments beforehand.
(at around 42 mins) When Blade tussles with Krieger in the club kitchen, padding is clearly exposed from Krieger's sleeves throughout the scene.
(at around 10 mins) In the beginning club scene after Blade has lit 'Quinn' on fire, he turns around and it is immediately visible that it is not Wesley Snipes but rather his stand-in.
Obvious stunt double for Deacon Frost in the final fight. In various scenes, his stunt double (Clayton J. Barber) can easily be recognized. He is skinnier, has different hair, no red eyes and less blood on his face.
Blade breaks through hospital roof top door which is obviously wood as bullets are seen going through it but after Blade and Karen have cleared the door it becomes metal as the marks from bullets now show that they didn't pass through.
(at around 1h 50 mins) When a single small drop of vampire blood on a microscope slide and one drop of EDTA solution are sufficient to blow up a microscope, the explosive force of a whole vampire full with about an ounce or two of EDTA should proportionally produce a far bigger explosion than shown, at least on the order of magnitude of a large hand grenade.
In the opening scene in the hospital, when Blades mother is in labor, as the doctor opens the door, his hand slips from the handle and he almost smashes his face into the trolley, but makes a smooth save and the mistake is often unnoticed.
In the opening scene (set in 1967) when Blade's mother is being wheeled into the hospital, one of the actors (portraying EMS) pushing the gurney has a shoulder patch with the blue Star of Life on it. The NHTSA, which EMS falls under, registered the blue Star of Life as a certification mark on February 1, 1977. Before that date, early EMS used a red cross with four bars, or an orange variant.
(at around 45 mins) When Deacon Frost has decoded the text, and is looking at the image of the chamber, and the positions the purebloods must stand in are being shown with a click for each one, there are 21 clicks, but only 12 purebloods are needed, plus one position at the centre for Deacon.
(at around 1h 12 mins) Shortly before Blade snatches the disoriented little girl out from in front of the approaching bus, you hear it shift up and the engine speed picking up for several seconds. IOW the driver is accelerating hard on the gas. Strange reaction when somebody appears in front of your vehicle.
(at around 1h 50 mins) When Blade silently mouths "What... the... fuck?", the crew is reflected in his sunglasses.
(at around 56 mins) In the subway, Mercury's dress changes from white to blue back to white again due to the ultraviolet lights that were used to light some of the SFX shots (lights that wouldn't normally exist in a subway tunnel).
When the policemen opens fire at Blade carrying Dr. Jensen away from the hospital, a crewman's arms with a paintball gun can clearly be seen in the right edge of the clip.
When Dragonetti is killed by the sun, the sun rises over the Pacific, in the west.
Deacon Frost was easily able to dodge bullets in the park so he should have been able to effortlessly dodge any attack from Blade.
The biggest plot hole in Deacon Frost's plan is that if everyone on the planet was going to be turned, vampires wouldn't have a food supply. They would have no choice but to turn on each other. In essence, they would be the cause of their own extinction.
It is established & shown that Blade possesses super strength due to his half vampire blood line. It is evident early on in the movie when he throws Dr. Jensen clearly across from one building rooftop to another building rooftop. A distance of at least a couple of hundred feet. This is an impressive level of strength. Yet when Whistler hands him the the updated U.V. Lamp, Blade complains that it's still heavy.
(at around 47 mins) When Blade and Karen head in to meet Pearl, the boom mic dips down into frame.
(at around 44 mins) When Blade and Karen enter the elevator to go to Pearl's, you can see Blade get out of character and joke with Karen as the doors close.
(at around 25 mins) Whistler tells Blade that he's checked Karen's background and found out that she's a hematologist. Since the word "hematologist" was printed on the name tag pinned to Karen's white coat, this fact should already have been apparent.
(at around 15 mins) When Karen tells Blade that her shoulder is dislocated, he moves to fix it; but she hadn't actually told him which shoulder it was.