# What is the mass of a single erythrocyte?

I really have been searching through internet on different languages, but can’t find any article that answers on the question what is the single erythrocyte mass. I don’t know, I think it’s pretty easy to calculate experimentally, but I didn’t find anything.

Has anyone measured single erythrocyte mass, and if yes, what is the value?

My try

Experimentally

I am not biologist or medical student. What do I know: blood consists of liquid part(water, salt) and solid part(red blood cells, white blood cells and thrombocytes). If It is possible, the white cells and thrombocytes can be moved off the blood in some test tube, so that will left only erythrocytes. Then, there should be medical statistical value like erythrocyte density or number of erythrocytes per liter.

We have some blood with only erythrocytes, we know how many erythrocyte are there. We can measure that blood weight, substrate the liquid weight(somehow), divide by erythrocyte number and will get the mass of a single erythrocyte.

Theoretically

About 90% of erythrocyte mass is hemoglobin. Hemoglobin is a molecule. Molecule is a countable thing, so, perhaps there is information about how many hemoglobin molecules, in average, is in one erythrocyte.

According to Angelo D’Alessandro, Monika Dzieciatkowska, Travis Nemkov, and Kirk C. Hansen article Red blood cell proteomics update: is there more to discover? it is about 270 millions per red blood cell. Molecular mass of hemoglobin is about $$64 kDa$$, absolute mass equals $$1.106*10^{-22} kg$$.

If my assumptions are correct, then 90% of erythrocyte mass is about $$2.97*10^{-14} kg$$

• If you can’t find the mass (and I wouldn’t imagine there’s a lot of interest in that, but obviously it interests you) you could presumably calculate it from the cell dimensions, assuming a density of about 1. Not a simple sphere, I know, but it should be possible. May 23, 2020 at 22:13
• Is your problem that you wish (or have been asked) to separate them? If so, you need to search for a term like "centrifugation of blood" or "fractionation of blood". Is this Wikipedia article any use as a starting point? And the English in your title is misleading: I would suggest you replace "separate" by "individual" or "single". May 24, 2020 at 8:46
• @David, I am not a biologist, or medical worker, I can’t do that May 24, 2020 at 9:01
• The volume and the density of erythrocytes should be known. May 24, 2020 at 9:30
• OK, I've made a calculation. You could check the arithmetic. But do tell me, why do you wish to know this? May 24, 2020 at 11:20

It’s not my kind of biology, and I tend to make mistakes in arithmetic, I’ll have a go…

I found a paper by Leblond and Shoucri published in the Journal of Microscopy (1978) 113, 161-170, entitled Calculation of surface area and volume of human erythrocytes from scanning electron micrographs. You need institutional access to read it, but for the human erythrocyte shown below they calculated:

Volume = 85.5 μm3 They found a range of sizes (65 μm3 in another image) so I shall take an average value of 75 μm3.

75 μm3 = 75 × 10–18 m3

Assuming a density of 1.1 g/cm3 for erythrocytes, i.e. 1.1 × 106 g/m3

Mass of an erythrocyte = 83 × 10–12 g (0.08 ng)

This is the same order of magnitude as that calculated later by the poster.

(Apologies for initially quoting the volume in pm3. No idea how I did that — it’s clearly μm3.)

• Unfortunately, wrong. $75pm^3=7.5*10^{-35} m^3$. May 24, 2020 at 11:28
• RBCs have a density of approx 1.110g/mL. Source: ncbi.nlm.nih.gov/pmc/articles/PMC5516969 May 24, 2020 at 11:30
• Also, volume, that equals $85 pm^3$ is interesting, because I found range $70-100 um^3$ May 24, 2020 at 11:30
• According, to that(another) “article “en.m.wikipedia.org/wiki/Mean_corpuscular_volume, average volume is $92.8 fL=92 um^3=9.2*10^{19} pm^3$ May 24, 2020 at 11:35
• @ArturKlochko Mea culpa. I see now, it's the pm as a whole that are cubed. Hunting down papers I can do, simple arithmetic as another matter... However now I seem to get an impossibly low answer of the order 10^–29g. Am adjourning for the moment. May 24, 2020 at 12:00

About 90% of erythrocyte mass is hemoglobin.

According to Angelo D’Alessandro, Monika Dzieciatkowska, Travis Nemkov, and Kirk C. Hansen article Red blood cell proteomics update: is there more to discover? there are about 270 millions hemoglobin molecules per red blood cell. Molecular mass of hemoglobin is about $$64 kDa$$, or $$1.106*10^{-22} kg$$.

From the given, 90% of erythrocyte mass is about $$2.97*10^{-14} kg$$

Now, using the proportion, calculate that the average erythrocyte mass is

$$m=\dfrac{2.97*10^{-14}kg*100\%}{90\%}=3.3*10^{-14} kg$$ $$erythocyte\space mass=33 pg$$

@David calculations result is also pretty similar to mine, He got $$83 pg$$